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Yuval O, Iosilevskii Y, Meledin A, Podbilewicz B, Shemesh T. Neuron tracing and quantitative analyses of dendritic architecture reveal symmetrical three-way-junctions and phenotypes of git-1 in C. elegans. PLoS Comput Biol 2021; 17:e1009185. [PMID: 34280180 PMCID: PMC8321406 DOI: 10.1371/journal.pcbi.1009185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 07/29/2021] [Accepted: 06/15/2021] [Indexed: 11/18/2022] Open
Abstract
Complex dendritic trees are a distinctive feature of neurons. Alterations to dendritic morphology are associated with developmental, behavioral and neurodegenerative changes. The highly-arborized PVD neuron of C. elegans serves as a model to study dendritic patterning; however, quantitative, objective and automated analyses of PVD morphology are missing. Here, we present a method for neuronal feature extraction, based on deep-learning and fitting algorithms. The extracted neuronal architecture is represented by a database of structural elements for abstracted analysis. We obtain excellent automatic tracing of PVD trees and uncover that dendritic junctions are unevenly distributed. Surprisingly, these junctions are three-way-symmetrical on average, while dendritic processes are arranged orthogonally. We quantify the effect of mutation in git-1, a regulator of dendritic spine formation, on PVD morphology and discover a localized reduction in junctions. Our findings shed new light on PVD architecture, demonstrating the effectiveness of our objective analyses of dendritic morphology and suggest molecular control mechanisms. Nerve cells (neurons) collect input signals via branched cellular projections called dendrites. A major aspect of the study of neurons, dating back over a century, involves the characterization of neuronal shapes and of their dendritic processes. Here, we present an algorithmic approach for detection and classification of the tree-like dendrites of the PVD neuron in C. elegans worms. A key feature of our approach is to represent dendritic trees by a set of fundamental shapes, such as junctions and linear elements. By analyzing this dataset, we discovered several novel structural features. We have found that the junctions connecting branched dendrites have a three-way-symmetry, although the dendrites are arranged in a crosshatch pattern, and that the distribution of junctions varies across distinct sub-classes of the PVD’s dendritic tree. We further quantified subtle morphological effects due to mutation in the git-1 gene, a known regulator of dendritic spines. Our findings suggest molecular mechanisms for dendritic shape regulation and may help direct new avenues of research.
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Affiliation(s)
- Omer Yuval
- Faculty of Biology, Technion–Israel Institute of Technology, Haifa, Israel
- School of Computing, Faculty of Engineering and Physical Sciences, University of Leeds, Leeds, United Kingdom
| | - Yael Iosilevskii
- Faculty of Biology, Technion–Israel Institute of Technology, Haifa, Israel
| | - Anna Meledin
- Faculty of Biology, Technion–Israel Institute of Technology, Haifa, Israel
| | - Benjamin Podbilewicz
- Faculty of Biology, Technion–Israel Institute of Technology, Haifa, Israel
- * E-mail: (BP); (TS)
| | - Tom Shemesh
- Faculty of Biology, Technion–Israel Institute of Technology, Haifa, Israel
- * E-mail: (BP); (TS)
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2
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Zheng X, Sun L, Liu B, Huang Z, Zhu Y, Chen T, Jia L, Li Y, Lei W. Morphological Study of the Cortical and Thalamic Glutamatergic Synaptic Inputs of Striatal Parvalbumin Interneurons in Rats. Neurochem Res 2021; 46:1659-1673. [PMID: 33770320 DOI: 10.1007/s11064-021-03302-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 02/14/2021] [Accepted: 03/17/2021] [Indexed: 10/21/2022]
Abstract
Parvalbumin-immunoreactive (Parv+) interneurons is an important component of striatal GABAergic microcircuits, which receive excitatory inputs from the cortex and thalamus, and then target striatal projection neurons. The present study aimed to examine ultrastructural synaptic connection features of Parv+ neruons with cortical and thalamic input, and striatal projection neurons by using immuno-electron microscopy (immuno-EM) and immunofluorescence techniques. Our results showed that both Parv+ somas and dendrites received numerous asymmetric synaptic inputs, and Parv+ terminals formed symmetric synapses with Parv- somas, dendrites and spine bases. Most interestingly, spine bases targeted by Parv+ terminals simultaneously received excitatory inputs at their heads. Electrical stimulation of the motor cortex (M1) induced higher proportion of striatal Parv+ neurons express c-Jun than stimulation of the parafascicular nucleus (PFN), and indicated that cortical- and thalamic-inputs differentially modulate Parv+ neurons. Consistent with that, both Parv + soma and dendrites received more VGlut1+ than VGlut2+ terminals. However, the proportion of VGlut1+ terminal targeting onto Parv+ proximal and distal dendrites was not different, but VGlut2+ terminals tended to target Parv+ somas and proximal dendrites than distal dendrites. These functional and morphological results suggested excitatory cortical and thalamic glutamatergic inputs differently modulate Parv+ interneurons, which provided inhibition inputs onto striatal projection neurons. To maintain the balance between the cortex and thalamus onto Parv+ interneurons may be an important therapeutic target for neurological disorders.
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Affiliation(s)
- Xuefeng Zheng
- Department of Anatomy, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China
- Department of Anatomy, Neuroscience Laboratory for Cognitive and Developmental Disorders, Medical College of Jinan University, Guangzhou, China
| | - Liping Sun
- Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Bingbing Liu
- Department of Anesthesiology, Guangdong Second Provincial General Hospital, Guangzhou, China
- The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China
| | - Ziyun Huang
- Department of Anatomy, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China
| | - Yaofeng Zhu
- Department of Anatomy, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China
- Institute of Medicine, College of Medicine, Jishou University, Jishou, China
| | - Tao Chen
- Department of Anatomy, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China
| | - Linju Jia
- Department of Anatomy, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China
| | - Yanmei Li
- Department of Anatomy, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China
| | - Wanlong Lei
- Department of Anatomy, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China.
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3
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Katsurabayashi S, Oyabu K, Kubota K, Watanabe T, Nagamatsu T, Akaike N, Iwasaki K. The novel mitochondria activator, 10-ethyl-3-methylpyrimido[4,5-b]quinoline-2,4(3H,10H)-dione (TND1128), promotes the development of hippocampal neuronal morphology. Biochem Biophys Res Commun 2021; 560:146-151. [PMID: 33989906 DOI: 10.1016/j.bbrc.2021.04.132] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 04/29/2021] [Indexed: 01/17/2023]
Abstract
Adenosine triphosphate (ATP) is the most vital energy source produced mainly in the mitochondria. Age-related mitochondrial dysfunction is associated with brain diseases. Nicotinamide adenine dinucleotide (NAD+) is an essential cofactor for energy production in mitochondria. Here, we examined how the novel NAD+-assisting substance, 10-ethyl-3-methylpyrimido[4,5-b]quinoline-2,4(3H,10H)-dione (TND1128), modulates the morphological growth of cultured mouse hippocampal neurons. The morphological growth effect of TND1128 was also compared with that of β-nicotinamide mononucleotide (β-NMN). TND1128 induced the branching of axons and dendrites, and increased the number of excitatory synapses. This study provides new insight into TND1128 as a mitochondria-stimulating drug for improving brain function.
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Affiliation(s)
- Shutaro Katsurabayashi
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka, 814-0180, Japan.
| | - Kohei Oyabu
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka, 814-0180, Japan
| | - Kaori Kubota
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka, 814-0180, Japan; A.I.G. Collaborative Research Institute for Aging and Brain Sciences, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka, 814-0180, Japan
| | - Takuya Watanabe
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka, 814-0180, Japan; A.I.G. Collaborative Research Institute for Aging and Brain Sciences, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka, 814-0180, Japan
| | - Tomohisa Nagamatsu
- Laboratory of Curative Medicine Creation Study for Geriatric-diseases Prevention, Faculty of Pharmaceutical Sciences, Sojo University, 4-22-1 Ikeda, Nishi-ku, Kumamoto, 860-0082, Japan; Chemiteras, Inc., 3-24-5 Shin-yokohama, Kohoku-ku, Yokohama, Kanagawa, 222-0033, Japan
| | - Norio Akaike
- Chemiteras, Inc., 3-24-5 Shin-yokohama, Kohoku-ku, Yokohama, Kanagawa, 222-0033, Japan; Research Division for Clinical Pharmacology, Medical Corporation, Juryo Group, Kumamoto Kinoh Hospital, 6-8-1 Yamamuro, Kita-ku, Kumamoto, 860-8518, Japan; Research Division of Neurophysiology, Kitamoto Hospital, 3-7-6, Kawarasone, Koshigaya, Saitama, 343-0821, Japan
| | - Katsunori Iwasaki
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka, 814-0180, Japan; A.I.G. Collaborative Research Institute for Aging and Brain Sciences, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka, 814-0180, Japan
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4
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Paik SK, Yoshida A, Bae YC. Development of γ-aminobutyric acid-, glycine-, and glutamate-immunopositive boutons on the rat genioglossal motoneurons. Brain Struct Funct 2021; 226:889-900. [PMID: 33475854 DOI: 10.1007/s00429-021-02216-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 01/08/2021] [Indexed: 12/13/2022]
Abstract
Detailed information about the development of excitatory and inhibitory synapses on the genioglossal (GG) motoneuron may help to understand the mechanism of fine control of GG motoneuron firing and the coordinated tongue movement during postnatal development. For this, we investigated the development of γ-aminobutyric acid (GABA)-immunopositive (GABA +), glycine + (Gly +), and glutamate + (Glut +) axon terminals (boutons) on the somata of rat GG motoneurons at a postnatal day 2 (P2), P6 and P18 by retrograde labeling of GG motoneurons with horseradish peroxidase, electron microscopic postembedding immunogold staining with GABA, Gly, and Glut antisera, and quantitative analysis. The number of boutons per GG motoneuron somata and the mean length of bouton apposition, measures of bouton size and synaptic covering percentage, were significantly increased from P2/P6 to P18. The number and fraction of GABA + only boutons of all boutons decreased significantly, whereas those of Gly + only boutons increased significantly from P2/P6 to P18, suggesting developmental switch from GABAergic to glycinergic synaptic transmission. The fraction of mixed GABA +/Gly + boutons of all boutons was the highest among inhibitory bouton types throughout the postnatal development. The fractions of excitatory and inhibitory boutons of all boutons remained unchanged during postnatal development. These findings reveal a distinct developmental pattern of inhibitory synapses on the GG motoneurons different from that on spinal or trigeminal motoneurons, which may have an important role in the regulation of the precise and coordinated movements of the tongue during the maturation of the oral motor system.
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Affiliation(s)
- Sang Kyoo Paik
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, 188-1, 2-Ga, Samdeok-Dong, Jung-Gu, Daegu, 700-412, Korea
| | - Atsushi Yoshida
- Department of Oral Anatomy and Neurobiology, Graduate School of Dentistry, Osaka University, Osaka, 565-0871, Japan
| | - Yong Chul Bae
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, 188-1, 2-Ga, Samdeok-Dong, Jung-Gu, Daegu, 700-412, Korea.
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5
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Robayo Avendaño O, Alvira Botero X, Garzón M. Ultrastructural evidence for mu and delta opioid receptors at noradrenergic dendrites and glial profiles in the cat locus coeruleus. Brain Res 2021; 1762:147443. [PMID: 33745926 DOI: 10.1016/j.brainres.2021.147443] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 02/01/2021] [Accepted: 03/13/2021] [Indexed: 11/17/2022]
Abstract
The Locus Coeruleus (LC) is a pontine nucleus involved in many physiological processes, including the control of the sleep/wake cycle (SWC). At cellular level, the LC displays a high density of opioid receptors whose activation decreases the activity of LC noradrenergic neurons. Also, microinjections of morphine administered locally in the LC of the cat produce sleep associated with synchronized brain activity in the electroencephalogram (EEG). Even though much of the research on sleep has been done in the cat, the subcellular location of opioid receptors in the LC and their relationship with LC noradrenergic neurons is not known yet in this species. Therefore, we conducted a study to describe the ultrastructural localization of mu-opioid receptors (MOR), delta-opioid receptors (DOR) and tyrosine hydroxylase (TH) in the cat LC using high resolution electron microscopy double-immunocytochemical detection. MOR and DOR were localized mainly in dendrites (45% and 46% of the total number of profiles respectively), many of which were noradrenergic (35% and 53% for MOR and DOR, respectively). TH immunoreactivity was more frequent in dendrites (65% of the total number of profiles), which mostly also expressed opioid receptors (58% and 73% for MOR and DOR, respectively). Because the distribution of MORs and DORs are similar, it is possible that a substantial sub-population of neurons co-express both receptors, which may facilitate the formation of MOR-DOR heterodimers. Moreover, we found differences in the cat subcellular DOR distribution compared with the rat. This opens the possibility to the existence of diverse mechanisms for opioid modulation of LC activity.
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Affiliation(s)
- Omar Robayo Avendaño
- Universidad Pedagógica y Tecnológica de Colombia. Antiguo Hospital San Rafael, 150001 Tunja, Colombia.
| | - Ximena Alvira Botero
- Universidad Autónoma de Madrid, Calle del Arzobispo Morcillo 4, 28029 Madrid, Spain
| | - Miguel Garzón
- Universidad Autónoma de Madrid, Calle del Arzobispo Morcillo 4, 28029 Madrid, Spain
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6
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Sethuramanujam S, Matsumoto A, deRosenroll G, Murphy-Baum B, Grosman C, McIntosh JM, Jing M, Li Y, Berson D, Yonehara K, Awatramani GB. Rapid multi-directed cholinergic transmission in the central nervous system. Nat Commun 2021; 12:1374. [PMID: 33654091 PMCID: PMC7925691 DOI: 10.1038/s41467-021-21680-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 01/27/2021] [Indexed: 01/31/2023] Open
Abstract
In many parts of the central nervous system, including the retina, it is unclear whether cholinergic transmission is mediated by rapid, point-to-point synaptic mechanisms, or slower, broad-scale 'non-synaptic' mechanisms. Here, we characterized the ultrastructural features of cholinergic connections between direction-selective starburst amacrine cells and downstream ganglion cells in an existing serial electron microscopy data set, as well as their functional properties using electrophysiology and two-photon acetylcholine (ACh) imaging. Correlative results demonstrate that a 'tripartite' structure facilitates a 'multi-directed' form of transmission, in which ACh released from a single vesicle rapidly (~1 ms) co-activates receptors expressed in multiple neurons located within ~1 µm of the release site. Cholinergic signals are direction-selective at a local, but not global scale, and facilitate the transfer of information from starburst to ganglion cell dendrites. These results suggest a distinct operational framework for cholinergic signaling that bears the hallmarks of synaptic and non-synaptic forms of transmission.
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Affiliation(s)
| | - Akihiro Matsumoto
- Danish Research Institute of Translational Neuroscience - DANDRITE, Nordic-EMBL Partnership for Molecular Medicine, Department of Biomedicine, Aarhus University, Aarhus C, Denmark
| | | | | | - Claudio Grosman
- Department of Molecular and Integrative Physiology, 407 S. Goodwin Ave, Urbana, IL, 61801, USA
| | - J Michael McIntosh
- George E. Whalen Veterans Affairs Medical Center, Department of Psychiatry, School of Biological Sciences, University of Utah, Salt Lake City, UT, USA
- Department of Psychiatry; School of Biological Sciences, University of Utah, Salt Lake City, UT, USA
- School of Biological Sciences, University of Utah, Salt Lake City, UT, USA
| | - Miao Jing
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing, China
| | - Yulong Li
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing, China
| | - David Berson
- Neuroscience, Brown University, Providence, RI, USA
| | - Keisuke Yonehara
- Danish Research Institute of Translational Neuroscience - DANDRITE, Nordic-EMBL Partnership for Molecular Medicine, Department of Biomedicine, Aarhus University, Aarhus C, Denmark.
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7
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Abstract
Aging is characterized by a decline in neuronal function in all animal species investigated so far. Functional changes are accompanied by and may be in part caused by, structurally visible degenerative changes in neurons. In the mammalian brain, normal aging shows abnormalities in dendrites and axons, as well as ultrastructural changes in synapses, rather than global neuron loss. The analysis of the structural features of aging neurons, as well as their causal link to molecular mechanisms on the one hand, and the functional decline on the other hand is crucial in order to understand the aging process in the brain. Invertebrate model organisms like Drosophila and C. elegans offer the opportunity to apply a forward genetic approach to the analysis of aging. In the present review, we aim to summarize findings concerning abnormalities in morphology and ultrastructure in invertebrate brains during normal aging and compare them to what is known for the mammalian brain. It becomes clear that despite of their considerably shorter life span, invertebrates display several age-related changes very similar to the mammalian condition, including the retraction of dendritic and axonal branches at specific locations, changes in synaptic density and increased accumulation of presynaptic protein complexes. We anticipate that continued research efforts in invertebrate systems will significantly contribute to reveal (and possibly manipulate) the molecular/cellular pathways leading to neuronal aging in the mammalian brain.
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Affiliation(s)
- Sandra C Koch
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles (UCLA), Los Angeles, California, USA
| | - Annie Nelson
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles (UCLA), Los Angeles, California, USA
| | - Volker Hartenstein
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles (UCLA), Los Angeles, California, USA.
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8
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Hisano K, Kawase S, Mimura T, Yoshida H, Yamada H, Haniu H, Tsukahara T, Kurihara T, Matsuda Y, Saito N, Uemura T. Structurally different lysophosphatidylethanolamine species stimulate neurite outgrowth in cultured cortical neurons via distinct G-protein-coupled receptors and signaling cascades. Biochem Biophys Res Commun 2021; 534:179-185. [PMID: 33298313 DOI: 10.1016/j.bbrc.2020.11.119] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 11/29/2020] [Indexed: 12/31/2022]
Abstract
Neurite outgrowth is important in neuronal circuit formation and functions, and for regeneration of neuronal networks following trauma and disease in the brain. Thus, identification and characterization of the molecules that regulate neurite outgrowth are essential for understanding how brain circuits form and function and for the development of treatment of neurological disorders. In this study, we found that structurally different lysophosphatidylethanolamine (LPE) species, palmitoyl-LPE (16:0 LPE) and stearoyl-LPE (18:0 LPE), stimulate neurite growth in cultured cortical neurons. Interestingly, YM-254890, an inhibitor of Gq/11 protein, inhibited 16:0 LPE-stimulated neurite outgrowth but not 18:0 LPE-stimulated neurite outgrowth. In contrast, pertussis toxin, an inhibitor of Gi/Go proteins, inhibited 18:0 LPE-stimulated neurite outgrowth but not 16:0 LPE-stimulated neurite outgrowth. The effects of protein kinase C inhibitors on neurite outgrowth were also different. In addition, both 16:0 LPE and 18:0 LPE activate mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase 1/2, but the effect of the MAPK inhibitor differed between the 16:0 LPE- and 18:0 LPE-treated cultures. Collectively, the results suggest that the structurally different LPE species, 16:0 LPE and 18:0 LPE stimulate neurite outgrowth through distinct signaling cascades in cultured cortical neurons and that distinct G protein-coupled receptors are involved in these processes.
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Affiliation(s)
- Kazutoshi Hisano
- Graduate School of Medicine, Science and Technology, Department of Biomedical Engineering, Shinshu University, Nagano, 390-8621, Japan; Institute for Biomedical Sciences, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, Nagano, 390-8621, Japan
| | - Shiori Kawase
- Division of Gene Research, Research Center for Supports to Advanced Science, Shinshu University, Nagano, 390-8621, Japan
| | - Tetsuhiko Mimura
- Department of Orthopaedic Surgery, Shinshu University School of Medicine, Nagano, 390-8621, Japan
| | - Hironori Yoshida
- Graduate School of Medicine, Science and Technology, Department of Biomedical Engineering, Shinshu University, Nagano, 390-8621, Japan; Institute for Biomedical Sciences, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, Nagano, 390-8621, Japan
| | - Hiroki Yamada
- Shinshu University School of Medicine, Nagano, 390-8621, Japan
| | - Hisao Haniu
- Institute for Biomedical Sciences, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, Nagano, 390-8621, Japan
| | - Tamotsu Tsukahara
- Department of Pharmacology and Therapeutic Innovation, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, 852-8521, Japan
| | - Taiga Kurihara
- Division of Microbiology and Molecular Cell Biology, Nihon Pharmaceutical University, Saitama, 362-0806, Japan
| | - Yoshikazu Matsuda
- Division of Clinical Pharmacology and Pharmaceutics, Nihon Pharmaceutical University, Saitama, 362-0806, Japan
| | - Naoto Saito
- Institute for Biomedical Sciences, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, Nagano, 390-8621, Japan
| | - Takeshi Uemura
- Institute for Biomedical Sciences, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, Nagano, 390-8621, Japan; Division of Gene Research, Research Center for Supports to Advanced Science, Shinshu University, Nagano, 390-8621, Japan.
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9
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Kuan AT, Phelps JS, Thomas LA, Nguyen TM, Han J, Chen CL, Azevedo AW, Tuthill JC, Funke J, Cloetens P, Pacureanu A, Lee WCA. Dense neuronal reconstruction through X-ray holographic nano-tomography. Nat Neurosci 2020; 23:1637-1643. [PMID: 32929244 PMCID: PMC8354006 DOI: 10.1038/s41593-020-0704-9] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 08/05/2020] [Indexed: 12/21/2022]
Abstract
Imaging neuronal networks provides a foundation for understanding the nervous system, but resolving dense nanometer-scale structures over large volumes remains challenging for light microscopy (LM) and electron microscopy (EM). Here we show that X-ray holographic nano-tomography (XNH) can image millimeter-scale volumes with sub-100-nm resolution, enabling reconstruction of dense wiring in Drosophila melanogaster and mouse nervous tissue. We performed correlative XNH and EM to reconstruct hundreds of cortical pyramidal cells and show that more superficial cells receive stronger synaptic inhibition on their apical dendrites. By combining multiple XNH scans, we imaged an adult Drosophila leg with sufficient resolution to comprehensively catalog mechanosensory neurons and trace individual motor axons from muscles to the central nervous system. To accelerate neuronal reconstructions, we trained a convolutional neural network to automatically segment neurons from XNH volumes. Thus, XNH bridges a key gap between LM and EM, providing a new avenue for neural circuit discovery.
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Affiliation(s)
- Aaron T Kuan
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Jasper S Phelps
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
- Program in Neuroscience, Harvard University, Boston, MA, USA
| | - Logan A Thomas
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Tri M Nguyen
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Julie Han
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Chiao-Lin Chen
- Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Anthony W Azevedo
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA
| | - John C Tuthill
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA
| | - Jan Funke
- HHMI Janelia Research Campus, Ashburn, VA, USA
| | | | - Alexandra Pacureanu
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA.
- ESRF, The European Synchrotron, Grenoble, France.
| | - Wei-Chung Allen Lee
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.
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10
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Crosta CM, Hernandez K, Bhattiprolu AK, Fu AY, Moore JC, Clarke SG, Dudzinski NR, Brzustowicz LM, Paradiso KG, Firestein BL. Characterization hiPSC-derived neural progenitor cells and neurons to investigate the role of NOS1AP isoforms in human neuron dendritogenesis. Mol Cell Neurosci 2020; 109:103562. [PMID: 32987141 PMCID: PMC7736313 DOI: 10.1016/j.mcn.2020.103562] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 09/02/2020] [Accepted: 09/22/2020] [Indexed: 01/30/2023] Open
Abstract
Abnormal dendritic arbor development has been implicated in a number of neurodevelopmental disorders, such as autism and Rett syndrome, and the neuropsychiatric disorder schizophrenia. Postmortem brain samples from subjects with schizophrenia show elevated levels of NOS1AP in the dorsolateral prefrontal cortex, a region of the brain associated with cognitive function. We previously reported that the long isoform of NOS1AP (NOS1AP-L), but not the short isoform (NOS1AP-S), negatively regulates dendrite branching in rat hippocampal neurons. To investigate the role that NOS1AP isoforms play in human dendritic arbor development, we adapted methods to generate human neural progenitor cells and neurons using induced pluripotent stem cell (iPSC) technology. We found that increased protein levels of either NOS1AP-L or NOS1AP-S decrease dendrite branching in human neurons at the developmental time point when primary and secondary branching actively occurs. Next, we tested whether pharmacological agents can decrease the expression of NOS1AP isoforms. Treatment of human iPSC-derived neurons with d-serine, but not clozapine, haloperidol, fluphenazine, or GLYX-13, results in a reduction in endogenous NOS1AP-L, but not NOS1AP-S, protein expression; however, d-serine treatment does not reverse decreases in dendrite number mediated by overexpression of NOS1AP isoforms. In summary, we demonstrate how an in vitro model of human neuronal development can help in understanding the etiology of schizophrenia and can also be used as a platform to screen drugs for patients.
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Affiliation(s)
- Christen M Crosta
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, Piscataway, NJ, USA; Neurosciences Graduate Program, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
| | - Kristina Hernandez
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, Piscataway, NJ, USA; Molecular Biosciences Graduate Program, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
| | - Atul K Bhattiprolu
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
| | - Allen Y Fu
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
| | - Jennifer C Moore
- Department of Genetics, Rutgers, The State University of New Jersey, 604 Allison Road, Piscataway, NJ 08854-8082, USA
| | - Stephen G Clarke
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
| | - Natasha R Dudzinski
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
| | - Linda M Brzustowicz
- Department of Genetics, Rutgers, The State University of New Jersey, 604 Allison Road, Piscataway, NJ 08854-8082, USA
| | - Kenneth G Paradiso
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
| | - Bonnie L Firestein
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, Piscataway, NJ, USA.
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11
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Kirov SA, Fomitcheva IV, Sword J. Rapid Neuronal Ultrastructure Disruption and Recovery during Spreading Depolarization-Induced Cytotoxic Edema. Cereb Cortex 2020; 30:5517-5531. [PMID: 32483593 PMCID: PMC7566686 DOI: 10.1093/cercor/bhaa134] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 04/08/2020] [Accepted: 04/29/2020] [Indexed: 01/29/2023] Open
Abstract
Two major pathogenic events that cause acute brain damage during neurologic emergencies of stroke, head trauma, and cardiac arrest are spreading depolarizing waves and the associated brain edema that course across the cortex injuring brain cells. Virtually nothing is known about how spreading depolarization (SD)-induced cytotoxic edema evolves at the ultrastructural level immediately after insult and during recovery. In vivo 2-photon imaging followed by quantitative serial section electron microscopy was used to assess synaptic circuit integrity in the neocortex of urethane-anesthetized male and female mice during and after SD evoked by transient bilateral common carotid artery occlusion. SD triggered a rapid fragmentation of dendritic mitochondria. A large increase in the density of synapses on swollen dendritic shafts implies that some dendritic spines were overwhelmed by swelling or merely retracted. The overall synaptic density was unchanged. The postsynaptic dendritic membranes remained attached to axonal boutons, providing a structural basis for the recovery of synaptic circuits. Upon immediate reperfusion, cytotoxic edema mainly subsides as affirmed by a recovery of dendritic ultrastructure. Dendritic recuperation from swelling and reversibility of mitochondrial fragmentation suggests that neurointensive care to improve tissue perfusion should be paralleled by treatments targeting mitochondrial recovery and minimizing the occurrence of SDs.
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Affiliation(s)
- Sergei A Kirov
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA
- Department of Neurosurgery, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA
| | - Ioulia V Fomitcheva
- Department of Neurosurgery, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA
| | - Jeremy Sword
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA
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12
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Ang MJ, Kang S, Moon C. Melatonin alters neuronal architecture and increases cysteine-rich protein 1 signaling in the male mouse hippocampus. J Neurosci Res 2020; 98:2333-2348. [PMID: 32754943 DOI: 10.1002/jnr.24708] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 07/13/2020] [Accepted: 07/19/2020] [Indexed: 01/10/2023]
Abstract
Neuronal plasticity describes changes in structure, function, and connections of neurons. The hippocampus, in particular, has been shown to exhibit considerable plasticity regarding both physiological and morphological functions. Melatonin, a hormone released by the pineal gland, promotes cell survival and dendrite maturation of neurons in the newborn brain and protects against neurological disorders. In this study, we investigated the effect of exogenous melatonin on neuronal architecture and its possible mechanism in the hippocampus of adult male C57BL/6 mice. Melatonin treatment significantly increased the total length and complexity of dendrites in the apical and basal cornu ammonis (CA) 1 and in the dentate gyrus in mouse hippocampi. Spine density in CA1 apical dendrites was increased, but no significant differences in other subregions were observed. In primary cultured hippocampal neurons, the length and arborization of neurites were significantly augmented by melatonin treatment. Additionally, western blot and immunohistochemical analyses in both in vivo and in vitro systems revealed significant increases in the level of cysteine-rich protein 1 (crp-1) protein, which is known to be involved in dendritic branching in mouse hippocampal neurons after melatonin treatment. Our results suggest that exogenous melatonin leads to significant alterations of neuronal micromorphometry in the adult hippocampus, possibly via crp-1 signaling.
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Affiliation(s)
- Mary Jasmin Ang
- Department of Veterinary Anatomy and Animal Behavior, College of Veterinary Medicine and BK21 Plus Project Team, Chonnam National University, Gwangju, South Korea
| | - Sohi Kang
- Department of Veterinary Anatomy and Animal Behavior, College of Veterinary Medicine and BK21 Plus Project Team, Chonnam National University, Gwangju, South Korea
| | - Changjong Moon
- Department of Veterinary Anatomy and Animal Behavior, College of Veterinary Medicine and BK21 Plus Project Team, Chonnam National University, Gwangju, South Korea
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13
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Hu C, Kanellopoulos AK, Richter M, Petersen M, Konietzny A, Tenedini FM, Hoyer N, Cheng L, Poon CLC, Harvey KF, Windhorst S, Parrish JZ, Mikhaylova M, Bagni C, Calderon de Anda F, Soba P. Conserved Tao Kinase Activity Regulates Dendritic Arborization, Cytoskeletal Dynamics, and Sensory Function in Drosophila. J Neurosci 2020; 40:1819-1833. [PMID: 31964717 PMCID: PMC7046460 DOI: 10.1523/jneurosci.1846-19.2020] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 01/13/2020] [Accepted: 01/16/2020] [Indexed: 12/11/2022] Open
Abstract
Dendritic arborization is highly regulated and requires tight control of dendritic growth, branching, cytoskeletal dynamics, and ion channel expression to ensure proper function. Abnormal dendritic development can result in altered network connectivity, which has been linked to neurodevelopmental disorders, including autism spectrum disorders (ASDs). How neuronal growth control programs tune dendritic arborization to ensure function is still not fully understood. Using Drosophila dendritic arborization (da) neurons as a model, we identified the conserved Ste20-like kinase Tao as a negative regulator of dendritic arborization. We show that Tao kinase activity regulates cytoskeletal dynamics and sensory channel localization required for proper sensory function in both male and female flies. We further provide evidence for functional conservation of Tao kinase, showing that its ASD-linked human ortholog, Tao kinase 2 (Taok2), could replace Drosophila Tao and rescue dendritic branching, dynamic microtubule alterations, and behavioral defects. However, several ASD-linked Taok2 variants displayed impaired rescue activity, suggesting that Tao/Taok2 mutations can disrupt sensory neuron development and function. Consistently, we show that Tao kinase activity is required in developing and as well as adult stages for maintaining normal dendritic arborization and sensory function to regulate escape and social behavior. Our data suggest an important role for Tao kinase signaling in cytoskeletal organization to maintain proper dendritic arborization and sensory function, providing a strong link between developmental sensory aberrations and behavioral abnormalities relevant for Taok2-dependent ASDs.SIGNIFICANCE STATEMENT Autism spectrum disorders (ASDs) are linked to abnormal dendritic arbors. However, the mechanisms of how dendritic arbors develop to promote functional and proper behavior are unclear. We identified Drosophila Tao kinase, the ortholog of the ASD risk gene Taok2, as a regulator of dendritic arborization in sensory neurons. We show that Tao kinase regulates cytoskeletal dynamics, controls sensory ion channel localization, and is required to maintain somatosensory function in vivo Interestingly, ASD-linked human Taok2 mutations rendered it nonfunctional, whereas its WT form could restore neuronal morphology and function in Drosophila lacking endogenous Tao. Our findings provide evidence for a conserved role of Tao kinase in dendritic development and function of sensory neurons, suggesting that aberrant sensory function might be a common feature of ASDs.
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Affiliation(s)
- Chun Hu
- Neuronal Patterning and Connectivity Laboratory, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | | | - Melanie Richter
- Neuronal Development Laboratory, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Meike Petersen
- Neuronal Patterning and Connectivity Laboratory, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Anja Konietzny
- Neuronal Protein Transport Laboratory, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Federico M Tenedini
- Neuronal Patterning and Connectivity Laboratory, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Nina Hoyer
- Neuronal Patterning and Connectivity Laboratory, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Lin Cheng
- Neuronal Patterning and Connectivity Laboratory, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Carole L C Poon
- Peter MacCallum Cancer Centre, Melbourne, 3000 Victoria, Australia
| | - Kieran F Harvey
- Peter MacCallum Cancer Centre, Melbourne, 3000 Victoria, Australia
- Department of Anatomy and Developmental Biology, and Biomedicine Discovery Institute, Monash University, Clayton, 3800 Victoria, Australia
| | - Sabine Windhorst
- Center for Experimental Medicine, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Jay Z Parrish
- Department of Biology, University of Washington, Seattle, 98195 Washington, and
| | - Marina Mikhaylova
- Neuronal Protein Transport Laboratory, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Claudia Bagni
- Department of Fundamental Neurosciences, University of Lausanne, 1005 Lausanne, Switzerland
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, 00133 Rome, Italy
| | - Froylan Calderon de Anda
- Neuronal Development Laboratory, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Peter Soba
- Neuronal Patterning and Connectivity Laboratory, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany,
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14
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Menon KP, Kulkarni V, Takemura SY, Anaya M, Zinn K. Interactions between Dpr11 and DIP-γ control selection of amacrine neurons in Drosophila color vision circuits. eLife 2019; 8:e48935. [PMID: 31692445 PMCID: PMC6879306 DOI: 10.7554/elife.48935] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 11/05/2019] [Indexed: 12/17/2022] Open
Abstract
Drosophila R7 UV photoreceptors (PRs) are divided into yellow (y) and pale (p) subtypes. yR7 PRs express the Dpr11 cell surface protein and are presynaptic to Dm8 amacrine neurons (yDm8) that express Dpr11's binding partner DIP-γ, while pR7 PRs synapse onto DIP-γ-negative pDm8. Dpr11 and DIP-γ expression patterns define 'yellow' and 'pale' color vision circuits. We examined Dm8 neurons in these circuits by electron microscopic reconstruction and expansion microscopy. DIP-γ and dpr11 mutations affect the morphologies of yDm8 distal ('home column') dendrites. yDm8 neurons are generated in excess during development and compete for presynaptic yR7 PRs, and interactions between Dpr11 and DIP-γ are required for yDm8 survival. These interactions also allow yDm8 neurons to select yR7 PRs as their appropriate home column partners. yDm8 and pDm8 neurons do not normally compete for survival signals or R7 partners, but can be forced to do so by manipulation of R7 subtype fate.
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Affiliation(s)
- Kaushiki P Menon
- Division of Biology and Biological EngineeringCalifornia Institute of TechnologyPasadenaUnited States
| | - Vivek Kulkarni
- Division of Biology and Biological EngineeringCalifornia Institute of TechnologyPasadenaUnited States
| | - Shin-ya Takemura
- Janelia Research CampusHoward Hughes Medical InstituteAshburnUnited States
| | - Michael Anaya
- Division of Biology and Biological EngineeringCalifornia Institute of TechnologyPasadenaUnited States
| | - Kai Zinn
- Division of Biology and Biological EngineeringCalifornia Institute of TechnologyPasadenaUnited States
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15
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Fernandez A, Meechan DW, Karpinski BA, Paronett EM, Bryan CA, Rutz HL, Radin EA, Lubin N, Bonner ER, Popratiloff A, Rothblat LA, Maynard TM, LaMantia AS. Mitochondrial Dysfunction Leads to Cortical Under-Connectivity and Cognitive Impairment. Neuron 2019; 102:1127-1142.e3. [PMID: 31079872 PMCID: PMC6668992 DOI: 10.1016/j.neuron.2019.04.013] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 02/21/2019] [Accepted: 04/03/2019] [Indexed: 12/17/2022]
Abstract
Under-connectivity between cerebral cortical association areas may underlie cognitive deficits in neurodevelopmental disorders, including the 22q11.2 deletion syndrome (22q11DS). Using the LgDel 22q11DS mouse model, we assessed cellular, molecular, and developmental origins of under-connectivity and its consequences for cognitive function. Diminished 22q11 gene dosage reduces long-distance projections, limits axon and dendrite growth, and disrupts mitochondrial and synaptic integrity in layer 2/3 but not 5/6 projection neurons (PNs). Diminished dosage of Txnrd2, a 22q11 gene essential for reactive oxygen species catabolism in brain mitochondria, recapitulates these deficits in WT layer 2/3 PNs; Txnrd2 re-expression in LgDel layer 2/3 PNs rescues them. Anti-oxidants reverse LgDel- or Txnrd2-related layer 2/3 mitochondrial, circuit, and cognitive deficits. Accordingly, Txnrd2-mediated oxidative stress reduces layer 2/3 connectivity and impairs cognition in the context of 22q11 deletion. Anti-oxidant restoration of mitochondrial integrity, cortical connectivity, and cognitive behavior defines oxidative stress as a therapeutic target in neurodevelopmental disorders.
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Affiliation(s)
- Alejandra Fernandez
- GW Institute for Neuroscience, The George Washington University, Washington, DC 20037, USA; Department of Anatomy and Regenerative Biology, The George Washington University, Washington, DC 20037, USA; GW Institute for Biomedical Sciences, School of Medicine and Health Sciences, The George Washington University, Washington, DC 20037, USA
| | - Daniel W Meechan
- GW Institute for Neuroscience, The George Washington University, Washington, DC 20037, USA; Department of Anatomy and Regenerative Biology, The George Washington University, Washington, DC 20037, USA
| | - Beverly A Karpinski
- GW Institute for Neuroscience, The George Washington University, Washington, DC 20037, USA; Department of Anatomy and Regenerative Biology, The George Washington University, Washington, DC 20037, USA
| | - Elizabeth M Paronett
- GW Institute for Neuroscience, The George Washington University, Washington, DC 20037, USA; Department of Anatomy and Regenerative Biology, The George Washington University, Washington, DC 20037, USA
| | - Corey A Bryan
- GW Institute for Neuroscience, The George Washington University, Washington, DC 20037, USA; Department of Anatomy and Regenerative Biology, The George Washington University, Washington, DC 20037, USA
| | - Hanna L Rutz
- Department of Psychology, The George Washington University, Washington, DC 20037, USA
| | - Eric A Radin
- GW Institute for Neuroscience, The George Washington University, Washington, DC 20037, USA; Department of Anatomy and Regenerative Biology, The George Washington University, Washington, DC 20037, USA
| | - Noah Lubin
- GW Institute for Neuroscience, The George Washington University, Washington, DC 20037, USA; Department of Anatomy and Regenerative Biology, The George Washington University, Washington, DC 20037, USA
| | - Erin R Bonner
- GW Institute for Neuroscience, The George Washington University, Washington, DC 20037, USA; Department of Anatomy and Regenerative Biology, The George Washington University, Washington, DC 20037, USA
| | - Anastas Popratiloff
- GW Institute for Neuroscience, The George Washington University, Washington, DC 20037, USA
| | - Lawrence A Rothblat
- GW Institute for Neuroscience, The George Washington University, Washington, DC 20037, USA; Department of Psychology, The George Washington University, Washington, DC 20037, USA
| | - Thomas M Maynard
- GW Institute for Neuroscience, The George Washington University, Washington, DC 20037, USA; Department of Anatomy and Regenerative Biology, The George Washington University, Washington, DC 20037, USA
| | - Anthony-Samuel LaMantia
- GW Institute for Neuroscience, The George Washington University, Washington, DC 20037, USA; Department of Anatomy and Regenerative Biology, The George Washington University, Washington, DC 20037, USA.
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16
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Paik SK, Yoo HI, Choi SK, Bae JY, Park SK, Bae YC. Distribution of excitatory and inhibitory axon terminals on the rat hypoglossal motoneurons. Brain Struct Funct 2019; 224:1767-1779. [PMID: 31006070 DOI: 10.1007/s00429-019-01874-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 04/11/2019] [Indexed: 12/19/2022]
Abstract
Detailed information about the excitatory and inhibitory synapses on the hypoglossal motoneurons may help understand the neural mechanism for control of the hypoglossal motoneuron excitability and hence the precise and coordinated movements of the tongue during chewing, swallowing and licking. For this, we investigated the distribution of GABA-, glycine (Gly)- and glutamate (Glut)-immunopositive (+) axon terminals on the genioglossal (GG) motoneurons by retrograde tracing, electron microscopic immunohistochemistry, and quantitative analysis. Small GG motoneurons (< 400 μm2 in cross-sectional area) had fewer primary dendrites, significantly higher nuclear/cytoplasmic ratio, and smaller membrane area covered by synaptic boutons than large GG motoneurons (> 400 μm2). The fraction of inhibitory boutons (GABA + only, Gly + only, and mixed GABA +/Gly + boutons) of all boutons was significantly higher for small GG motoneurons than for large ones, whereas the fraction of Glut + boutons was significantly higher for large GG motoneurons than for small ones. Almost all boutons (> 95%) on both small and large GG motoneurons were GABA + , Gly + or Glut + . The frequency of mixed GABA +/Gly + boutons was the highest among inhibitory boutons types for both small and large GG motoneurons. These findings may elucidate the anatomical substrate for precise regulation of the motoneuron firing required for the fine movements of the tongue, and also suggest that the excitability of small and large GG motoneurons may be regulated differently.
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Affiliation(s)
- Sang Kyoo Paik
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, 188-1, 2-Ga, Samdeok-Dong, Jung-Gu, Daegu, 700-412, South Korea
| | - Hong Il Yoo
- Department of Anatomy and Neuroscience, College of Medicine, Eulji University, 77 Gyeryong-ro 771 beon-gil, Jung-Gu, Daejeon, 34824, South Korea
| | - Seung Ki Choi
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, 188-1, 2-Ga, Samdeok-Dong, Jung-Gu, Daegu, 700-412, South Korea
| | - Jin Young Bae
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, 188-1, 2-Ga, Samdeok-Dong, Jung-Gu, Daegu, 700-412, South Korea
| | - Sook Kyung Park
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, 188-1, 2-Ga, Samdeok-Dong, Jung-Gu, Daegu, 700-412, South Korea
| | - Yong Chul Bae
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, 188-1, 2-Ga, Samdeok-Dong, Jung-Gu, Daegu, 700-412, South Korea.
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17
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Kim W, Won SY, Yoon BJ. CRMP2 mediates GSK3β actions in the striatum on regulating neuronal structure and mania-like behavior. J Affect Disord 2019; 245:1079-1088. [PMID: 30699850 DOI: 10.1016/j.jad.2018.10.371] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 09/29/2018] [Accepted: 10/05/2018] [Indexed: 11/20/2022]
Abstract
BACKGROUND Genetic and physiological studies have implicated the striatum in bipolar disorder (BD). Although Glycogen synthase kinase 3 beta (GSK3β) has been suggested to play a role in the pathophysiology of BD since it is inhibited by lithium, it remains unknown how GSK3β activity might be involved. Therefore we examined the functional roles of GSK3β and one of its substrates, CRMP2, within the striatum. METHODS Using CRISPR-Cas9 system, we specifically ablated GSK3β in the striatal neurons in vivo and in vitro. Sholl analysis was performed for the structural studies of medium spiny neurons (MSNs) and amphetamine-induced hyperlocomotion was measured to investigate the effects of gene ablations on the mania-like symptom of BD. RESULTS GSK3β deficiency in cultured neurons and in neurons of adult mouse brain caused opposite patterns of neurite changes. Furthermore, specific knockout of GSK3β in the MSNs of the indirect pathway significantly suppressed amphetamine-induced hyperlocomotion. We demonstrated that these phenotypes of GSK3β ablation were mediated by CRMP2, a major substrate of GSK3β. LIMITATIONS Amphetamine-induced hyperlocomotion only partially recapitulate the symptoms of BD. It requires further study to examine whether abnormality in GSK3β or CRMP2 is also involved in depression phase of BD. Additionally, we could not confirm whether the behavioral changes observed in GSK3β-ablated mice were indeed caused by the cellular structural changes observed in the striatal neurons. CONCLUSION Our results demonstrate that GSK3β and its substrate CRMP2 critically regulate the neurite structure of MSNs and their functions specifically within the indirect pathway of the basal ganglia network play a critical role in manifesting mania-like behavior of BD. Moreover, our data also suggest lithium may exert its effect on BD through a GSK3β-independent mechanism, in addition to the GSK3β inhibition-mediated mechanism.
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Affiliation(s)
- Wonju Kim
- Division of Life Sciences, School of Life Sciences and Biotechnology, Korea University, Anam-ro 145, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Seong-Yeon Won
- Division of Life Sciences, School of Life Sciences and Biotechnology, Korea University, Anam-ro 145, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Bong-June Yoon
- Division of Life Sciences, School of Life Sciences and Biotechnology, Korea University, Anam-ro 145, Seongbuk-gu, Seoul 02841, Republic of Korea.
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18
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Ratliff WA, Mervis RF, Citron BA, Schwartz B, Rubovitch V, Schreiber S, Pick CG. Mild blast-related TBI in a mouse model alters amygdalar neurostructure and circuitry. Exp Neurol 2019; 315:9-14. [PMID: 30711646 DOI: 10.1016/j.expneurol.2019.01.020] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 01/16/2019] [Accepted: 01/30/2019] [Indexed: 02/07/2023]
Abstract
Traumatic brain injury (TBI) continues to be a signature injury of our modern conflicts. Due in part to increased use of improvised explosive devices (IEDs), we have seen blast trauma make up a significant portion of TBIs sustained by deployed troops and civilians. In addition to the physical injury, TBI is also a common comorbidity with post-traumatic stress disorder (PTSD). Previous research suggests that PTSD is often associated with increased signaling within the amygdala, leading to feelings of fear and hyperarousal. In our study, we utilized a mouse model of mild blast-related TBI (bTBI) to investigate how TBI induces changes within the amygdala, which may provide favorable conditions for the development of PTSD. To do this, we performed Golgi staining on the stellate neurons of the basolateral amygdala and quantified dendritic amount, distribution, and complexity. We found increases in dendritic branching and in the density of dendritic spines in injured mice. Increases in spine density appears to be primarily due to increases in memory associated mushroom type dendritic spines. These changes observed in our bTBI model that are consistent with chronic stress models, suggesting an important connection between the physical changes induced by TBI and the neurological symptoms of PTSD.
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Affiliation(s)
- Whitney A Ratliff
- Bay Pines VA Healthcare System, Research and Development, 151, Bldg. 22 Rm. 123, 10000 Bay Pines Blvd, Bay Pines, FL 33744, USA; Department of Molecular Medicine, USF College of Medicine, 12901 Bruce B. Downs Blvd, MDC 7, Tampa, FL 33612, USA.
| | - Ronald F Mervis
- NeuroStructural Analytics, Inc., Columbus, OH, USA; Center for Aging and Brain Repair, Department of Neurosurgery and Brain Repair, University of South Florida Morsani College of Medicine, 2 Tampa General Circle, Tampa, FL 33606, USA
| | - Bruce A Citron
- Bay Pines VA Healthcare System, Research and Development, 151, Bldg. 22 Rm. 123, 10000 Bay Pines Blvd, Bay Pines, FL 33744, USA; Department of Molecular Medicine, USF College of Medicine, 12901 Bruce B. Downs Blvd, MDC 7, Tampa, FL 33612, USA; VA New Jersey Health Care System, Research & Development, Mailstop 15, Bldg. 16, Rm. 16-176, 385 Tremont Ave, East Orange, NJ 07018, USA; Department of Pharmacology, Physiology & Neuroscience, Rutgers- New Jersey Medical School, 185 South Orange Ave., Newark, NJ 07101, USA
| | - Brian Schwartz
- Department of Anatomy and Anthropology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Vardit Rubovitch
- Department of Anatomy and Anthropology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Shaul Schreiber
- Department of Psychiatry, Tel Aviv Sourasky Medical Center, Tel Aviv 64239, Israel; Department of Psychiatry, Tel Aviv University Sackler Faculty of Medicine, Tel Aviv 64239, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Chaim G Pick
- Department of Anatomy and Anthropology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel; Dr. Miriam and Sheldon G. Adelson Chair, Center for the Biology of Addictive Diseases, Tel Aviv University, Tel Aviv 69978, Israel
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19
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Keith RE, Azcarate JM, Keith MJ, Hung CW, Badakhsh MF, Dumas TC. Direct Intracellular Signaling by the Carboxy terminus of NMDA Receptor GluN2 Subunits Regulates Dendritic Morphology in Hippocampal CA1 Pyramidal Neurons. Neuroscience 2019; 396:138-153. [PMID: 30471357 PMCID: PMC6311441 DOI: 10.1016/j.neuroscience.2018.11.021] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 10/16/2018] [Accepted: 11/14/2018] [Indexed: 12/22/2022]
Abstract
N-methyl-d-aspartate receptors (NMDARs) are glutamatergic receptors that take part in excitatory synaptic transmission and drive functional and structural neuronal plasticity, including activity-dependent changes in dendritic morphology. Forebrain NMDARs contribute to neuronal plasticity in at least two ways: through calcium-mediated processes or via direct intracellular postsynaptic signaling. Both properties are regulated by the GluN2 subunits. However, the separate contributions of these properties to the regulation of dendritic morphology are unknown. We created transgenic mice that express chimeric GluN2 subunits and examined the impact on pyramidal cell dendritic morphology in hippocampal region CA1. Golgi-Cox impregnation and transgenic expression of green fluorescent protein were employed to visualize dendritic arbors. In adult mice with a predominantly native GluN2A background, overexpression of the GluN2B carboxy terminus increased the total path of the dendritic arbor without affecting branch number or tortuosity. Overexpressing the amino terminus and transmembrane domains of GluN2B had little effect. It may be inferred from these results that NMDAR-dependent intracellular signaling regulates dendritic morphology of hippocampal pyramidal cells more so than calcium conductance dynamics. The findings add to the understanding of NMDAR-mediated signaling in hippocampal neurons and support re-investigation of the molecular underpinnings of NMDAR involvement in postnatal dendrite maturation.
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Affiliation(s)
- Rachel E Keith
- Interdisciplinary Program in Neuroscience, George Mason University, Fairfax, VA 22030, United States; Krasnow Institute of Advanced Study, George Mason University, Fairfax, VA 22030, United States
| | - Jessica M Azcarate
- Krasnow Institute of Advanced Study, George Mason University, Fairfax, VA 22030, United States
| | - Matthew J Keith
- Krasnow Institute of Advanced Study, George Mason University, Fairfax, VA 22030, United States
| | - Carey W Hung
- Krasnow Institute of Advanced Study, George Mason University, Fairfax, VA 22030, United States
| | - Maryam F Badakhsh
- Krasnow Institute of Advanced Study, George Mason University, Fairfax, VA 22030, United States
| | - Theodore C Dumas
- Psychology Department, George Mason University, Fairfax, VA 22030, United States; Interdisciplinary Program in Neuroscience, George Mason University, Fairfax, VA 22030, United States; Krasnow Institute of Advanced Study, George Mason University, Fairfax, VA 22030, United States.
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20
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Abstract
OBJECTIVE We implemented computational models of human and rat cortical neurons for simulating the neural response to cortical stimulation with electromagnetic fields. APPROACH We adapted model neurons from the library of Blue Brain models to reflect biophysical and geometric properties of both adult rat and human cortical neurons and coupled the model neurons to exogenous electric fields (E-fields). The models included 3D reconstructed axonal and dendritic arbors, experimentally-validated electrophysiological behaviors, and multiple, morphological variants within cell types. Using these models, we characterized the single-cell responses to intracortical microstimulation (ICMS) and uniform E-field with dc as well as pulsed currents. MAIN RESULTS The strength-duration and current-distance characteristics of the model neurons to ICMS agreed with published experimental results, as did the subthreshold polarization of cell bodies and axon terminals by uniform dc E-fields. For all forms of stimulation, the lowest threshold elements were terminals of the axon collaterals, and the dependence of threshold and polarization on spatial and temporal stimulation parameters was strongly affected by morphological features of the axonal arbor, including myelination, diameter, and branching. SIGNIFICANCE These results provide key insights into the mechanisms of cortical stimulation. The presented models can be used to study various cortical stimulation modalities while incorporating detailed spatial and temporal features of the applied E-field.
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Affiliation(s)
- Aman S Aberra
- Department of Biomedical Engineering, School of Engineering, Duke University, Durham, NC 27710, United States of America
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21
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Clark SG, Graybeal LL, Bhattacharjee S, Thomas C, Bhattacharya S, Cox DN. Basal autophagy is required for promoting dendritic terminal branching in Drosophila sensory neurons. PLoS One 2018; 13:e0206743. [PMID: 30395636 PMCID: PMC6218061 DOI: 10.1371/journal.pone.0206743] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 10/18/2018] [Indexed: 01/22/2023] Open
Abstract
Dendrites function as the primary sites for synaptic input and integration with impairments in dendritic arborization being associated with dysfunctional neuronal circuitry. Post-mitotic neurons require high levels of basal autophagy to clear cytotoxic materials and autophagic dysfunction under native or cellular stress conditions has been linked to neuronal cell death as well as axo-dendritic degeneration. However, relatively little is known regarding the developmental role of basal autophagy in directing aspects of dendritic arborization or the mechanisms by which the autophagic machinery may be transcriptionally regulated to promote dendritic diversification. We demonstrate that autophagy-related (Atg) genes are positively regulated by the homeodomain transcription factor Cut, and that basal autophagy functions as a downstream effector pathway for Cut-mediated dendritic terminal branching in Drosophila multidendritic (md) sensory neurons. Further, loss of function analyses implicate Atg genes in promoting cell type-specific dendritic arborization and terminal branching, while gain of function studies suggest that excessive autophagy leads to dramatic reductions in dendritic complexity. We demonstrate that the Atg1 initiator kinase interacts with the dual leucine zipper kinase (DLK) pathway by negatively regulating the E3 ubiquitin ligase Highwire and positively regulating the MAPKKK Wallenda. Finally, autophagic induction partially rescues dendritic atrophy defects observed in a model of polyglutamine toxicity. Collectively, these studies implicate transcriptional control of basal autophagy in directing dendritic terminal branching and demonstrate the importance of homeostatic control of autophagic levels for dendritic arbor complexity under native or cellular stress conditions.
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Affiliation(s)
- Sarah G. Clark
- Neuroscience Institute, Georgia State University, Atlanta, Georgia, United States of America
| | - Lacey L. Graybeal
- School of Systems Biology, Krasnow Institute for Advanced Study, George Mason University, Fairfax, Virginia, United States of America
| | - Shatabdi Bhattacharjee
- Neuroscience Institute, Georgia State University, Atlanta, Georgia, United States of America
| | - Caroline Thomas
- School of Systems Biology, Krasnow Institute for Advanced Study, George Mason University, Fairfax, Virginia, United States of America
| | - Surajit Bhattacharya
- Neuroscience Institute, Georgia State University, Atlanta, Georgia, United States of America
| | - Daniel N. Cox
- Neuroscience Institute, Georgia State University, Atlanta, Georgia, United States of America
- School of Systems Biology, Krasnow Institute for Advanced Study, George Mason University, Fairfax, Virginia, United States of America
- * E-mail:
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22
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Schneider ES, Kleineidam CJ, Leitinger G, Römer H. Ultrastructure and electrophysiology of thermosensitive sensilla coeloconica in a tropical katydid of the genus Mecopoda (Orthoptera, Tettigoniidae). Arthropod Struct Dev 2018; 47:482-497. [PMID: 30120986 DOI: 10.1016/j.asd.2018.08.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 08/11/2018] [Accepted: 08/13/2018] [Indexed: 06/08/2023]
Abstract
In many acoustic insects, mate finding and mate choice are primarily based on acoustic signals. In several species with high-intensity calling songs, such as the studied katydid Mecopoda sp., males exhibit an increase in their thoracic temperature during singing, which is linearly correlated with the amount of energy invested in song production. If this increased body temperature is used by females as an additional cue to assess the male's quality during mate choice, as has been recently hypothesized ("hot-male" hypothesis), thermosensory structures would be required to evaluate this cue. In the present study, therefore, we investigated the ultrastructure and physiology of thermosensitive sensilla coeloconica on the antennal flagella of Mecopoda sp. using a combination of electron microscopy and electrophysiological recording techniques. We could identify three distinct types of sensilla coeloconica based on differences in the number and branching pattern of their dendrites. Physiological recordings revealed the innervation by antagonistically responding thermoreceptors (cold and warm) and bimodal hygro-/thermoreceptors (moist or dry) in various combinations. Our findings indicate that Mecopoda sp. females are capable of detecting a singing male from distances of at least several centimetres solely by assessing thermal cues.
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Affiliation(s)
- Erik S Schneider
- Institute of Zoology, University of Graz, Universitätsplatz 2/1, 8010 Graz, Austria.
| | - Christoph J Kleineidam
- Behavioral Neurobiology, Department of Biology, University of Konstanz, 78457 Konstanz, Germany
| | - Gerd Leitinger
- Research Unit Electron Microscopic Techniques, Department of Cell Biology, Histology and Embryology, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6, 8010 Graz, Austria
| | - Heinrich Römer
- Institute of Zoology, University of Graz, Universitätsplatz 2/1, 8010 Graz, Austria
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Moore AM, Prescott M, Czieselsky K, Desroziers E, Yip SH, Campbell RE, Herbison AE. Synaptic Innervation of the GnRH Neuron Distal Dendron in Female Mice. Endocrinology 2018; 159:3200-3208. [PMID: 30010812 DOI: 10.1210/en.2018-00505] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 07/05/2018] [Indexed: 11/19/2022]
Abstract
GnRH neuron cell bodies are scattered throughout the basal forebrain but funnel their projections to the median eminence to release GnRH into the pituitary portal system to control fertility. Prior studies have shown that GnRH neurons located in the anterior hypothalamus send projections to the median eminence that have characteristics of both dendrites and axons. These unusual structures have been termed "dendrons." To address whether the dendron is unique to anterior hypothalamic GnRH neurons or is also a characteristic of more rostral GnRH neurons, we used viral vector‒mediated GnRH neuron‒specific tract-tracing coupled with CLARITY optical clearing. Individual rostral preoptic area GnRH neurons in female mice were identified to elaborate processes up to 4 mm in length that exhibited spines and projected all the way to the median eminence before branching into multiple short axons. The synaptic innervation patterns of distal GnRH neuron dendrons and their short axons in the vicinity of the median eminence were examined using electron microscopy. This revealed the presence of a high density of synaptic inputs to distal dendrons at the border of the median eminence. In contrast, no synapses were detected on any GnRH neuron axons. These studies demonstrate that GnRH neurons in the rostral preoptic area project dendrons to the edge of the median eminence, whereupon they branch into multiple short axons responsible for GnRH secretion. The dense synaptic innervation of these distal dendrons likely represents an efficient mechanism for controlling GnRH secretion required for fertility.
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Affiliation(s)
- Aleisha M Moore
- Centre for Neuroendocrinology, Department of Physiology, Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand
| | - Mel Prescott
- Centre for Neuroendocrinology, Department of Physiology, Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand
| | - Katja Czieselsky
- Centre for Neuroendocrinology, Department of Physiology, Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand
| | - Elodie Desroziers
- Centre for Neuroendocrinology, Department of Physiology, Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand
| | - Siew Hoong Yip
- Centre for Neuroendocrinology, Department of Physiology, Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand
| | - Rebecca E Campbell
- Centre for Neuroendocrinology, Department of Physiology, Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand
| | - Allan E Herbison
- Centre for Neuroendocrinology, Department of Physiology, Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand
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Zong W, Wang Y, Tang Q, Zhang H, Yu F. Prd1 associates with the clathrin adaptor α-Adaptin and the kinesin-3 Imac/Unc-104 to govern dendrite pruning in Drosophila. PLoS Biol 2018; 16:e2004506. [PMID: 30142146 PMCID: PMC6126864 DOI: 10.1371/journal.pbio.2004506] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Revised: 09/06/2018] [Accepted: 08/03/2018] [Indexed: 11/18/2022] Open
Abstract
Refinement of the nervous system depends on selective removal of excessive axons/dendrites, a process known as pruning. Drosophila ddaC sensory neurons prune their larval dendrites via endo-lysosomal degradation of the L1-type cell adhesion molecule (L1-CAM), Neuroglian (Nrg). Here, we have identified a novel gene, pruning defect 1 (prd1), which governs dendrite pruning of ddaC neurons. We show that Prd1 colocalizes with the clathrin adaptor protein α-Adaptin (α-Ada) and the kinesin-3 immaculate connections (Imac)/Uncoordinated-104 (Unc-104) in dendrites. Moreover, Prd1 physically associates with α-Ada and Imac, which are both critical for dendrite pruning. Prd1, α-Ada, and Imac promote dendrite pruning via the regulation of endo-lysosomal degradation of Nrg. Importantly, genetic interactions among prd1, α-adaptin, and imac indicate that they act in the same pathway to promote dendrite pruning. Our findings indicate that Prd1, α-Ada, and Imac act together to regulate discrete distribution of α-Ada/clathrin puncta, facilitate endo-lysosomal degradation, and thereby promote dendrite pruning in sensory neurons. During the maturation of the nervous system, some neurons can selectively eliminate their unnecessary connections, including dendrites and axons, to retain specific connections. In Drosophila, a class of sensory neurons lose all their larval dendrites during metamorphosis, when they transition from larvae to adults. We previously showed that these neurons prune their dendrites via lysosome-mediated degradation of a cell-adhesion protein, Neuroglian. In this paper, we identified a previously uncharacterized gene, pruning defect 1 (prd1), which plays an important role in dendrite pruning. We show that Prd1 is localized and complexed with α-Adaptin and Imac, two other proteins that are also essential for dendrite pruning. Moreover, Prd1, α-Adaptin, and Imac act in a common pathway to promote dendrite pruning by down-regulating Neuroglian protein. Thus, our study highlights a mechanism whereby Prd1, α-Adaptin, and Imac act together to regulate distribution of α-Adaptin/clathrin puncta, facilitate lysosome-dependent protein degradation, and thereby promote dendrite pruning in Drosophila sensory neurons.
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Affiliation(s)
- Wenhui Zong
- Temasek Life Sciences Laboratory and Department of Biological Sciences, 1 Research Link, National University of Singapore, Singapore
| | - Yan Wang
- Temasek Life Sciences Laboratory and Department of Biological Sciences, 1 Research Link, National University of Singapore, Singapore
| | - Quan Tang
- Temasek Life Sciences Laboratory and Department of Biological Sciences, 1 Research Link, National University of Singapore, Singapore
| | - Heng Zhang
- Temasek Life Sciences Laboratory and Department of Biological Sciences, 1 Research Link, National University of Singapore, Singapore
| | - Fengwei Yu
- Temasek Life Sciences Laboratory and Department of Biological Sciences, 1 Research Link, National University of Singapore, Singapore
- NUS Graduate School for Integrative Sciences and Engineering, Centre for Life Sciences, Singapore
- Neuroscience and Behavioral Disorder Program, Duke-NUS Graduate Medical School Singapore, Singapore
- * E-mail:
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25
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Nunes D, Kuner T. Axonal sodium channel NaV1.2 drives granule cell dendritic GABA release and rapid odor discrimination. PLoS Biol 2018; 16:e2003816. [PMID: 30125271 PMCID: PMC6117082 DOI: 10.1371/journal.pbio.2003816] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 08/30/2018] [Accepted: 08/06/2018] [Indexed: 12/19/2022] Open
Abstract
Dendrodendritic synaptic interactions between olfactory bulb mitral and granule cells represent a key neuronal mechanism of odor discrimination. Dendritic release of gamma-aminobutyric acid (GABA) from granule cells contributes to stimulus-dependent, rapid, and accurate odor discrimination, yet the physiological mechanisms governing this release and its behavioral relevance are unknown. Here, we show that granule cells express the voltage-gated sodium channel α-subunit NaV1.2 in clusters distributed throughout the cell surface including dendritic spines. Deletion of NaV1.2 in granule cells abolished spiking and GABA release as well as inhibition of synaptically connected mitral cells (MCs). As a consequence, mice required more time to discriminate highly similar odorant mixtures, while odor discrimination learning remained unaffected. In conclusion, we show that expression of NaV1.2 in granule cells is crucial for physiological dendritic GABA release and rapid discrimination of similar odorants with high accuracy. Hence, our data indicate that neurotransmitter-releasing dendritic spines function just like axon terminals. In axonal nerve terminals, neurotransmitter release is triggered by a localized Ca2+ nanodomain generated by voltage-gated calcium channels in response to an action potential, which in turn is mediated by voltage-gated sodium channels. Dendritic neurotransmitter release has been thought to work differently, mainly depending on Ca2+ entering directly through N-methyl-D-aspartate (NMDA) receptors, a subtype of ligand-gated ion channel. To further investigate how dendritic neurotransmitter is released, we studied granule cells in the olfactory bulb of mice, which establish inhibitory dendrodendritic synapses with mitral cells. We show that granule cells express voltage-gated sodium channels predominantly localized in dendrites and spines. Down-regulation of these channels precludes action potential firing in granule cells and strongly reduces mitral cell inhibition. Behaviorally, these mice require more time to discriminate highly similar odorants at maximal accuracy. Therefore, the inhibition of mitral cells relies on neurotransmitter released from the dendrites of granule cells by a mechanism that resembles axonal neurotransmitter release much more than previously thought.
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Affiliation(s)
- Daniel Nunes
- Champalimaud Research, Champalimaud Centre for the Unknown, Lisbon, Portugal
- Functional Neuroanatomy Department, Institute for Anatomy and Cell Biology, Heidelberg University, Heidelberg, Germany
- * E-mail: (DN); (TK)
| | - Thomas Kuner
- Functional Neuroanatomy Department, Institute for Anatomy and Cell Biology, Heidelberg University, Heidelberg, Germany
- * E-mail: (DN); (TK)
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Sui S, Tian J, Gauba E, Wang Q, Guo L, Du H. Cyclophilin D regulates neuronal activity-induced filopodiagenesis by fine-tuning dendritic mitochondrial calcium dynamics. J Neurochem 2018; 146:403-415. [PMID: 29900530 PMCID: PMC6107423 DOI: 10.1111/jnc.14484] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 05/07/2018] [Accepted: 06/08/2018] [Indexed: 12/21/2022]
Abstract
Recent studies have highlighted the role of mitochondria in dendritic protrusion growth and plasticity. However, the detailed mechanisms that mitochondria regulate dendritic filopodia morphogenesis remain elusive. Cyclophilin D (CypD, gene name: Ppif) controls the opening of mitochondrial permeability transition pore. Although the pathological relevance of CypD has been intensively investigated, little is known about its physiological function in neurons. Here, we have found that genetic depletion of or pharmaceutical inhibition of CypD blunts the outgrowth of dendritic filopodia in response to KCl-stimulated neuronal depolarization. Further cell biological studies suggest that such inhibitory effect of CypD loss-of-function is closely associated with compromised flexibility of dendritic mitochondrial calcium regulation during neuronal depolarization, as well as the resultant changes in intradendritic calcium homeostasis, calcium signaling activation, dendritic mitochondrial motility and redistribution. Interestingly, loss of CypD attenuates oxidative stress-induced mitochondrial calcium perturbations and dendritic protrusion injury. Therefore, our study has revealed the physiological function of CypD in dendritic plasticity by acting as a fine-tuner of mitochondrial calcium homeostasis. Moreover, CypD plays distinct roles in neuronal physiology and pathology. Cover Image for this issue: doi: 10.1111/jnc.14189.
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Affiliation(s)
- Shaomei Sui
- AD Center, Department of Neurology, Qianfoshan Hospital Affiliated to Shandong University, Jinan, Shandong, China. 250014
- Department of Biological Sciences, The University of Texas at Dallas, 800 West Campbell Rd. Richardson, Texas. 75080
| | - Jing Tian
- Department of Biological Sciences, The University of Texas at Dallas, 800 West Campbell Rd. Richardson, Texas. 75080
| | - Esha Gauba
- Department of Biological Sciences, The University of Texas at Dallas, 800 West Campbell Rd. Richardson, Texas. 75080
| | - Qi Wang
- AD Center, Department of Neurology, Qianfoshan Hospital Affiliated to Shandong University, Jinan, Shandong, China. 250014
- Department of Biological Sciences, The University of Texas at Dallas, 800 West Campbell Rd. Richardson, Texas. 75080
| | - Lan Guo
- Department of Biological Sciences, The University of Texas at Dallas, 800 West Campbell Rd. Richardson, Texas. 75080
| | - Heng Du
- AD Center, Department of Neurology, Qianfoshan Hospital Affiliated to Shandong University, Jinan, Shandong, China. 250014
- Department of Biological Sciences, The University of Texas at Dallas, 800 West Campbell Rd. Richardson, Texas. 75080
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27
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Kahn OI, Schätzle P, van de Willige D, Tas RP, Lindhout FW, Portegies S, Kapitein LC, Hoogenraad CC. APC2 controls dendrite development by promoting microtubule dynamics. Nat Commun 2018; 9:2773. [PMID: 30018294 PMCID: PMC6050278 DOI: 10.1038/s41467-018-05124-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Accepted: 06/12/2018] [Indexed: 12/12/2022] Open
Abstract
Mixed polarity microtubule organization is the signature characteristic of vertebrate dendrites. Oppositely oriented microtubules form the basis for selective cargo trafficking in neurons, however the mechanisms that establish and maintain this organization are unclear. Here, we show that APC2, the brain-specific homolog of tumor-suppressor protein adenomatous polyposis coli (APC), promotes dynamics of minus-end-out microtubules in dendrites. We found that APC2 localizes as distinct clusters along microtubule bundles in dendrites and that this localization is driven by LC8-binding and two separate microtubule-interacting domains. Depletion of APC2 reduces the plus end dynamics of minus-end-out oriented microtubules, increases microtubule sliding, and causes defects in dendritic morphology. We propose a model in which APC2 regulates dendrite development by promoting dynamics of minus-end-out microtubules.
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Affiliation(s)
- Olga I Kahn
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, 3584 CH, Utrecht, The Netherlands
| | - Philipp Schätzle
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, 3584 CH, Utrecht, The Netherlands
| | - Dieudonnée van de Willige
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, 3584 CH, Utrecht, The Netherlands
| | - Roderick P Tas
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, 3584 CH, Utrecht, The Netherlands
| | - Feline W Lindhout
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, 3584 CH, Utrecht, The Netherlands
| | - Sybren Portegies
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, 3584 CH, Utrecht, The Netherlands
| | - Lukas C Kapitein
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, 3584 CH, Utrecht, The Netherlands
| | - Casper C Hoogenraad
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, 3584 CH, Utrecht, The Netherlands.
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Lázaro J, Hertel M, Sherwood CC, Muturi M, Dechmann DKN. Profound seasonal changes in brain size and architecture in the common shrew. Brain Struct Funct 2018; 223:2823-2840. [PMID: 29663134 PMCID: PMC5995987 DOI: 10.1007/s00429-018-1666-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 04/10/2018] [Indexed: 11/28/2022]
Abstract
The seasonal changes in brain size of some shrews represent the most drastic reversible transformation in the mammalian central nervous system known to date. Brain mass decreases 10-26% from summer to winter and regrows 9-16% in spring, but the underlying structural changes at the cellular level are not yet understood. Here, we describe the volumetric differences in brain structures between seasons and sexes of the common shrew (Sorex araneus) in detail, confirming that changes in different brain regions vary in the magnitude of change. Notably, shrews show a decrease in hypothalamus, thalamus, and hippocampal volume and later regrowth in spring, whereas neocortex and striatum volumes decrease in winter and do not recover in size. For some regions, males and females showed different patterns of seasonal change from each other. We also analyzed the underlying changes in neuron morphology. We observed a general decrease in soma size and total dendrite volume in the caudoputamen and anterior cingulate cortex. This neuronal retraction may partially explain the overall tissue shrinkage in winter. While not sufficient to explain the entire seasonal process, it represents a first step toward understanding the mechanisms beneath this remarkable phenomenon.
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Affiliation(s)
- Javier Lázaro
- Department of Migration and Immuno-Ecology, Max Planck Institute for Ornithology, 78315, Radolfzell, Germany.
- Department of Biology, University of Konstanz, 78457, Konstanz, Germany.
| | - Moritz Hertel
- Department of Behavioural Neurobiology, Max Planck Institute for Ornithology, 82319, Seewiesen, Germany
| | - Chet C Sherwood
- Department of Anthropology, The George Washington University, 20052, Washington, DC, USA
| | - Marion Muturi
- Department of Migration and Immuno-Ecology, Max Planck Institute for Ornithology, 78315, Radolfzell, Germany
- Department of Biology, University of Konstanz, 78457, Konstanz, Germany
| | - Dina K N Dechmann
- Department of Migration and Immuno-Ecology, Max Planck Institute for Ornithology, 78315, Radolfzell, Germany
- Department of Biology, University of Konstanz, 78457, Konstanz, Germany
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29
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Fitzgerald ML, Pickel VM. Adolescent isolation rearing produces a prepulse inhibition deficit correlated with expression of the NMDA GluN1 subunit in the nucleus accumbens. Brain Struct Funct 2018; 223:3169-3181. [PMID: 29779156 DOI: 10.1007/s00429-018-1673-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 04/27/2018] [Indexed: 12/18/2022]
Abstract
Adolescence is a transition period during which social interaction is necessary for normal brain and behavior development. Severely abnormal social interactions during adolescence can increase the incidence of lifelong psychiatric disease. Decreased prepulse inhibition (PPI) is a quantifiable hallmark of some psychiatric illnesses in humans and can be elicited in rodents by isolation rearing throughout the adolescent transition period. PPI is a measure of sensorimotor gating in which the nucleus accumbens (Acb) is crucially involved. The Acb is comprised of core and shell subregions, which receive convergent dopaminergic and glutamatergic inputs. To gain insight into the neurobiological correlates of adolescent adversity, we conducted electron microscopic immunolabeling of dopamine D1 receptors (D1Rs) and the GluN1 subunit of glutamate NMDA receptors in the Acb of isolation-reared (IR) adult male rats. In all animals, GluN1 was primarily located in dendritic profiles, many of which also contained D1Rs. GluN1 was also observed in perisynaptic glia and axon terminals. In IR rats compared with group-reared controls, GluN1 density was selectively decreased in D1R-containing dendrites of the Acb core. Across all animals, dendritic GluN1 density correlated with average percent PPI, implicating endogenous expression of NMDA receptors of the Acb as a possible substrate of the PPI response. These results suggest that adolescent isolation dampens NMDA-mediated excitation in direct (D1R-containing) output neurons of the Acb, and that these changes influence the operational measure of PPI.
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Affiliation(s)
- Megan L Fitzgerald
- Brain and Mind Research Institute, Weill Cornell Medicine, 407 East 61st Street, New York, NY, 10065, USA
- New York State Psychiatric Institute, Columbia University, New York, NY, 10032, USA
| | - Virginia M Pickel
- Brain and Mind Research Institute, Weill Cornell Medicine, 407 East 61st Street, New York, NY, 10065, USA.
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Bae JY, Lee JS, Ko SJ, Cho YS, Rah JC, Cho HJ, Park MJ, Bae YC. Extrasynaptic homomeric glycine receptors in neurons of the rat trigeminal mesencephalic nucleus. Brain Struct Funct 2018; 223:2259-2268. [PMID: 29460053 DOI: 10.1007/s00429-018-1607-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Accepted: 11/29/2017] [Indexed: 12/19/2022]
Abstract
The neurons in the trigeminal mesencephalic nucleus (Vmes) innervate jaw-closing muscle spindles and periodontal ligaments, and play a crucial role in the regulation of jaw movements. Recently, it was shown that many boutons that form synapses on them are immunopositive for glycine (Gly+), suggesting that these neurons receive glycinergic input. Information about the glycine receptors that mediate this input is needed to help understand the role of glycine in controlling Vmes neuron excitability. For this, we investigated the expression of glycine receptor subunit alpha 3 (GlyRα3) and gephyrin in neurons in Vmes and the trigeminal motor nucleus (Vmo), and the Gly+ boutons that contact them by light- and electron-microscopic immunocytochemistry and quantitative ultrastructural analysis. The somata of the Vmes neurons were immunostained for GlyRα3, but not gephyrin, indicating expression of homomeric GlyR. The immunostaining for GlyRα3 was localized away from the synapses in the Vmes neuron somata, in contrast to the Vmo neurons, where the staining for GlyRα3 and gephyrin were localized at the subsynaptic zones in somata and dendrites. Additionally, the ultrastructural determinants of synaptic strength, bouton volume, mitochondrial volume, and active zone area, were significantly smaller in Gly+ boutons on the Vmes neurons than in those on the Vmo neurons. These findings support the notion that the Vmes neurons receive glycinergic input via putative extrasynaptic homomeric glycine receptors, likely mediating a slow, tonic modulation of the Vmes neuron excitability.
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Affiliation(s)
- Jin Young Bae
- Department of Anatomy and Neurobiology, School of Medicine and Dentistry, Kyungpook National University, 188-1, 2-Ga, Samdeok-Dong, Jung-Gu, Daegu, 700-412, South Korea
| | - Jae Sik Lee
- Department of Anatomy and Neurobiology, School of Medicine and Dentistry, Kyungpook National University, 188-1, 2-Ga, Samdeok-Dong, Jung-Gu, Daegu, 700-412, South Korea
| | - Sang Jin Ko
- Department of Anatomy and Neurobiology, School of Medicine and Dentistry, Kyungpook National University, 188-1, 2-Ga, Samdeok-Dong, Jung-Gu, Daegu, 700-412, South Korea
| | - Yi Sul Cho
- Department of Anatomy and Neurobiology, School of Medicine and Dentistry, Kyungpook National University, 188-1, 2-Ga, Samdeok-Dong, Jung-Gu, Daegu, 700-412, South Korea
| | - Jong-Cheol Rah
- Korea Brian Research Institute, 61 Cheomdan-ro, Dong-gu, Daegu, 701-300, South Korea
| | - Hee Jung Cho
- Department of Anatomy and Neurobiology, School of Medicine and Dentistry, Kyungpook National University, 188-1, 2-Ga, Samdeok-Dong, Jung-Gu, Daegu, 700-412, South Korea
| | - Mae Ja Park
- Department of Anatomy and Neurobiology, School of Medicine and Dentistry, Kyungpook National University, 188-1, 2-Ga, Samdeok-Dong, Jung-Gu, Daegu, 700-412, South Korea
| | - Yong Chul Bae
- Department of Anatomy and Neurobiology, School of Medicine and Dentistry, Kyungpook National University, 188-1, 2-Ga, Samdeok-Dong, Jung-Gu, Daegu, 700-412, South Korea.
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Abstract
With the ability to correct for the aberrations introduced by biological specimens, adaptive optics-a method originally developed for astronomical telescopes-has been applied to optical microscopy to recover diffraction-limited imaging performance deep within living tissue. In particular, this technology has been used to improve image quality and provide a more accurate characterization of both structure and function of neurons in a variety of living organisms. Among its many highlights, adaptive optical microscopy has made it possible to image large volumes with diffraction-limited resolution in zebrafish larval brains, to resolve dendritic spines over 600μm deep in the mouse brain, and to more accurately characterize the orientation tuning properties of thalamic boutons in the primary visual cortex of awake mice.
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Affiliation(s)
- Cristina Rodríguez
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Na Ji
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA; Department of Physics, Department of Molecular & Cellular Biology, University of California, Berkeley, CA 94720, USA.
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Takács S, Bardóczi Z, Skrapits K, Göcz B, Váczi V, Maglóczky Z, Szűcs I, Rácz G, Matolcsy A, Dhillo WS, Watanabe M, Kádár A, Fekete C, Kalló I, Hrabovszky E. Post mortem single-cell labeling with DiI and immunoelectron microscopy unveil the fine structure of kisspeptin neurons in humans. Brain Struct Funct 2018; 223:2143-2156. [PMID: 29380121 DOI: 10.1007/s00429-018-1610-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 01/10/2018] [Indexed: 11/30/2022]
Abstract
Kisspeptin (KP) synthesizing neurons of the hypothalamic infundibular region are critically involved in the central regulation of fertility; these cells regulate pulsatile gonadotropin-releasing hormone (GnRH) secretion and mediate sex steroid feedback signals to GnRH neurons. Fine structural analysis of the human KP system is complicated by the use of post mortem tissues. To gain better insight into the neuroanatomy of the somato-dendritic cellular compartment, we introduced the diolistic labeling of immunohistochemically identified KP neurons using a gene gun loaded with the lipophilic dye, DiI. Confocal microscopic studies of primary dendrites in 100-µm-thick tissue sections established that 79.3% of KP cells were bipolar, 14.1% were tripolar, and 6.6% were unipolar. Primary dendrites branched sparsely, contained numerous appendages (9.1 ± 1.1 spines/100 µm dendrite), and received rich innervation from GABAergic, glutamatergic, and KP-containing terminals. KP neuron synaptology was analyzed with immunoelectron microscopy on perfusion-fixed specimens. KP axons established frequent contacts and classical synapses on unlabeled, and on KP-immunoreactive somata, dendrites, and spines. Synapses were asymmetric and the presynaptic structures contained round and regular synaptic vesicles, in addition to dense-core granules. Although immunofluorescent studies failed to detect vesicular glutamate transporter isoforms in KP axons, ultrastructural characteristics of synaptic terminals suggested use of glutamatergic, in addition to peptidergic, neurotransmission. In summary, immunofluorescent and DiI labeling of KP neurons in thick hypothalamic sections and immunoelectron microscopic studies of KP-immunoreactive neurons in brains perfusion-fixed shortly post mortem allowed us to identify previously unexplored fine structural features of KP neurons in the mediobasal hypothalamus of humans.
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Affiliation(s)
- Szabolcs Takács
- Laboratory of Reproductive Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, 43 Szigony St., Budapest, 1083, Hungary
| | - Zsuzsanna Bardóczi
- Laboratory of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
- School of PH.D. Studies, Semmelweis University, Budapest, Hungary
| | - Katalin Skrapits
- Laboratory of Reproductive Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, 43 Szigony St., Budapest, 1083, Hungary
| | - Balázs Göcz
- Laboratory of Reproductive Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, 43 Szigony St., Budapest, 1083, Hungary
| | - Viktória Váczi
- Laboratory of Reproductive Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, 43 Szigony St., Budapest, 1083, Hungary
| | - Zsófia Maglóczky
- Human Brain Research Laboratory, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
| | - Iván Szűcs
- Department of Pathology, St. Borbála Hospital, Tatabanya, Hungary
| | - Gergely Rácz
- 1st Department of Pathology and Experimental Cancer Research, Semmelweis University, Budapest, Hungary
| | - András Matolcsy
- 1st Department of Pathology and Experimental Cancer Research, Semmelweis University, Budapest, Hungary
| | - Waljit S Dhillo
- Department of Investigative Medicine, Hammersmith Hospital, Imperial College London, London, UK
| | - Masahiko Watanabe
- Department of Anatomy, Hokkaido University School of Medicine, Sapporo, Japan
| | - Andrea Kádár
- Laboratory of Integrative Neuroendocrinology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
| | - Csaba Fekete
- Laboratory of Integrative Neuroendocrinology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Tupper Research Institute, Tufts Medical Center, Boston, MA, USA
| | - Imre Kalló
- Laboratory of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
- Department of Neuroscience, Faculty of Information Technology, Pázmány Péter Catholic University, Budapest, Hungary
| | - Erik Hrabovszky
- Laboratory of Reproductive Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, 43 Szigony St., Budapest, 1083, Hungary.
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Praschberger R, Lowe SA, Malintan NT, Giachello CNG, Patel N, Houlden H, Kullmann DM, Baines RA, Usowicz MM, Krishnakumar SS, Hodge JJL, Rothman JE, Jepson JEC. Mutations in Membrin/GOSR2 Reveal Stringent Secretory Pathway Demands of Dendritic Growth and Synaptic Integrity. Cell Rep 2017; 21:97-109. [PMID: 28978487 PMCID: PMC5640804 DOI: 10.1016/j.celrep.2017.09.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Revised: 08/17/2017] [Accepted: 09/01/2017] [Indexed: 11/16/2022] Open
Abstract
Mutations in the Golgi SNARE (SNAP [soluble NSF attachment protein] receptor) protein Membrin (encoded by the GOSR2 gene) cause progressive myoclonus epilepsy (PME). Membrin is a ubiquitous and essential protein mediating ER-to-Golgi membrane fusion. Thus, it is unclear how mutations in Membrin result in a disorder restricted to the nervous system. Here, we use a multi-layered strategy to elucidate the consequences of Membrin mutations from protein to neuron. We show that the pathogenic mutations cause partial reductions in SNARE-mediated membrane fusion. Importantly, these alterations were sufficient to profoundly impair dendritic growth in Drosophila models of GOSR2-PME. Furthermore, we show that Membrin mutations cause fragmentation of the presynaptic cytoskeleton coupled with transsynaptic instability and hyperactive neurotransmission. Our study highlights how dendritic growth is vulnerable even to subtle secretory pathway deficits, uncovers a role for Membrin in synaptic function, and provides a comprehensive explanatory basis for genotype-phenotype relationships in GOSR2-PME.
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Affiliation(s)
- Roman Praschberger
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London, UK
| | - Simon A Lowe
- School of Physiology, Pharmacology, and Neuroscience, University of Bristol, Bristol, UK
| | - Nancy T Malintan
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London, UK
| | - Carlo N G Giachello
- Faculty of Biology, Medicine, and Health, Division of Neuroscience & Experimental Psychology, Manchester Academic Health Science Centre, University of Manchester, Manchester, UK
| | - Nian Patel
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London, UK
| | - Henry Houlden
- Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK
| | - Dimitri M Kullmann
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London, UK
| | - Richard A Baines
- Faculty of Biology, Medicine, and Health, Division of Neuroscience & Experimental Psychology, Manchester Academic Health Science Centre, University of Manchester, Manchester, UK
| | - Maria M Usowicz
- School of Physiology, Pharmacology, and Neuroscience, University of Bristol, Bristol, UK
| | - Shyam S Krishnakumar
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London, UK; Department of Cell Biology, Yale School of Medicine, New Haven, CT, USA
| | - James J L Hodge
- School of Physiology, Pharmacology, and Neuroscience, University of Bristol, Bristol, UK
| | - James E Rothman
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London, UK; Department of Cell Biology, Yale School of Medicine, New Haven, CT, USA
| | - James E C Jepson
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London, UK.
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Sun G, He Y, Ma XK, Li S, Chen D, Gao M, Qiu S, Yin J, Shi J, Wu J. Hippocampal synaptic and neural network deficits in young mice carrying the human APOE4 gene. CNS Neurosci Ther 2017; 23:748-758. [PMID: 28786172 PMCID: PMC6492660 DOI: 10.1111/cns.12720] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 06/24/2017] [Accepted: 06/25/2017] [Indexed: 02/05/2023] Open
Abstract
INTRODUCTION Apolipoprotein E4 (APOE4) is a major genetic risk factor for late-onset sporadic Alzheimer disease. Emerging evidence demonstrates a hippocampus-associated learning and memory deficit in aged APOE4 human carriers and also in aged mice carrying human APOE4 gene. This suggests that either exogenous APOE4 or endogenous APOE4 alters the cognitive profile and hippocampal structure and function. However, little is known regarding how Apoe4 modulates hippocampal dendritic morphology, synaptic function, and neural network activity in young mice. AIM In this study, we compared hippocampal dendritic and spine morphology and synaptic function of young (4 months) mice with transgenic expression of the human APOE4 and APOE3 genes. METHODS Hippocampal dendritic and spine morphology and synaptic function were assessed by neuronal imaging and electrophysiological approaches. RESULTS Morphology results showed that shortened dendritic length and reduced spine density occurred at hippocampal CA1 neurons in Apoe4 mice compared to Apoe3 mice. Electrophysiological results demonstrated that in the hippocampal CA3-CA1 synapses of young Apoe4 mice, basic synaptic transmission, and paired-pulse facilitation were enhanced but long-term potentiation and carbachol-induced hippocampal theta oscillations were impaired compared to young Apoe3 mice. However, both Apoe genotypes responded similarly to persistent stimulations (4, 10, and 40 Hz for 4 seconds). CONCLUSION Our results suggest significant alterations in hippocampal dendritic structure and synaptic function in Apoe4 mice, even at an early age.
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Affiliation(s)
- Guo‐Zhu Sun
- Department of NeurosurgeryThe Second Hospital of Hebei Medical UniversityShijiazhuangHebeiChina
- Department of NeurobiologyBarrow Neurological InstituteSt. Joseph's Hospital and Medical CenterPhoenixAZUSA
| | - Yong‐Chang He
- Department of NeurosurgeryThe Second Hospital of Hebei Medical UniversityShijiazhuangHebeiChina
- Department of NeurobiologyBarrow Neurological InstituteSt. Joseph's Hospital and Medical CenterPhoenixAZUSA
| | - Xiao Kuang Ma
- Department of NeurobiologyBarrow Neurological InstituteSt. Joseph's Hospital and Medical CenterPhoenixAZUSA
- Department of PhysiologyShantou University Medical CollegeShantouGuangdongChina
- Department of Basic Medical SciencesUniversity of Arizona College of MedicinePhoenixAZUSA
| | - Shuang‐Tao Li
- Department of NeurobiologyBarrow Neurological InstituteSt. Joseph's Hospital and Medical CenterPhoenixAZUSA
- Department of PhysiologyShantou University Medical CollegeShantouGuangdongChina
| | - De‐Jie Chen
- Department of NeurobiologyBarrow Neurological InstituteSt. Joseph's Hospital and Medical CenterPhoenixAZUSA
| | - Ming Gao
- Department of NeurobiologyBarrow Neurological InstituteSt. Joseph's Hospital and Medical CenterPhoenixAZUSA
| | - Shen‐Feng Qiu
- Department of Basic Medical SciencesUniversity of Arizona College of MedicinePhoenixAZUSA
| | - Jun‐Xiang Yin
- Department of NeurologyBarrow Neurological InstituteSt. Joseph's Hospital and Medical CenterPhoenixAZUSA
| | - Jiong Shi
- Department of NeurologyBarrow Neurological InstituteSt. Joseph's Hospital and Medical CenterPhoenixAZUSA
- Department of NeurologyTianjin Neurological InstituteTianjin Medical University General HospitalTianjinChina
| | - Jie Wu
- Department of NeurobiologyBarrow Neurological InstituteSt. Joseph's Hospital and Medical CenterPhoenixAZUSA
- Department of PhysiologyShantou University Medical CollegeShantouGuangdongChina
- Department of Basic Medical SciencesUniversity of Arizona College of MedicinePhoenixAZUSA
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Petralia RS, Wang YX, Mattson MP, Yao PJ. Invaginating Presynaptic Terminals in Neuromuscular Junctions, Photoreceptor Terminals, and Other Synapses of Animals. Neuromolecular Med 2017; 19:193-240. [PMID: 28612182 PMCID: PMC6518423 DOI: 10.1007/s12017-017-8445-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Accepted: 06/01/2017] [Indexed: 10/19/2022]
Abstract
Typically, presynaptic terminals form a synapse directly on the surface of postsynaptic processes such as dendrite shafts and spines. However, some presynaptic terminals invaginate-entirely or partially-into postsynaptic processes. We survey these invaginating presynaptic terminals in all animals and describe several examples from the central nervous system, including giant fiber systems in invertebrates, and cup-shaped spines, electroreceptor synapses, and some specialized auditory and vestibular nerve terminals in vertebrates. We then examine mechanoreceptors and photoreceptors, concentrating on the complex of pre- and postsynaptic processes found in basal invaginations of the cell. We discuss in detail the role of vertebrate invaginating horizontal cell processes in both chemical and electrical feedback mechanisms. We also discuss the common presence of indenting or invaginating terminals in neuromuscular junctions on muscles of most kinds of animals, and especially discuss those of Drosophila and vertebrates. Finally, we consider broad questions about the advantages of possessing invaginating presynaptic terminals and describe some effects of aging and disease, especially on neuromuscular junctions. We suggest that the invagination is a mechanism that can enhance both chemical and electrical interactions at the synapse.
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Affiliation(s)
- Ronald S Petralia
- Advanced Imaging Core, NIDCD/NIH, 35A Center Drive, Room 1E614, Bethesda, MD, 20892-3729, USA.
| | - Ya-Xian Wang
- Advanced Imaging Core, NIDCD/NIH, 35A Center Drive, Room 1E614, Bethesda, MD, 20892-3729, USA
| | - Mark P Mattson
- Laboratory of Neurosciences, NIA/NIH, Baltimore, MD, 21224, USA
| | - Pamela J Yao
- Laboratory of Neurosciences, NIA/NIH, Baltimore, MD, 21224, USA
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36
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Vormberg A, Effenberger F, Muellerleile J, Cuntz H. Universal features of dendrites through centripetal branch ordering. PLoS Comput Biol 2017; 13:e1005615. [PMID: 28671947 PMCID: PMC5515450 DOI: 10.1371/journal.pcbi.1005615] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Revised: 07/18/2017] [Accepted: 06/05/2017] [Indexed: 11/19/2022] Open
Abstract
Dendrites form predominantly binary trees that are exquisitely embedded in the networks of the brain. While neuronal computation is known to depend on the morphology of dendrites, their underlying topological blueprint remains unknown. Here, we used a centripetal branch ordering scheme originally developed to describe river networks—the Horton-Strahler order (SO)–to examine hierarchical relationships of branching statistics in reconstructed and model dendritic trees. We report on a number of universal topological relationships with SO that are true for all binary trees and distinguish those from SO-sorted metric measures that appear to be cell type-specific. The latter are therefore potential new candidates for categorising dendritic tree structures. Interestingly, we find a faithful correlation of branch diameters with centripetal branch orders, indicating a possible functional importance of SO for dendritic morphology and growth. Also, simulated local voltage responses to synaptic inputs are strongly correlated with SO. In summary, our study identifies important SO-dependent measures in dendritic morphology that are relevant for neural function while at the same time it describes other relationships that are universal for all dendrites. Similarly to river beds, dendritic trees of nerve cells form elaborate networks that branch out to cover extensive areas. In the 1940s, ecologist Robert E. Horton developed an ordering system for branches in river networks that was refined in the 1950s by geoscientist Arthur N. Strahler, the Horton-Strahler order (SO). Branches at the tips start with order 1 and increase their order in a systematic way when encountering new branches on the way to the root. SO relationships have recently become popular for quantifying dendritic morphologies. Various branching statistics can be studied as a function of SO. Here we describe that topological measures such as the number of branches, the branch bifurcation ratio and the size of subtrees exhibit stereotypical relations with SO in dendritic trees independently of cell type, mirroring universal features of binary trees. Other functionally more relevant features such as mean branch lengths, local diameters and simulated voltage responses to synaptic inputs directly correlate with SO in a cell type-specific manner, indicating the importance of SO for understanding dendrite growth as well as neural computation.
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Affiliation(s)
- Alexandra Vormberg
- Ernst Strüngmann Institute (ESI) for Neuroscience in Cooperation with Max Planck Society, Frankfurt/Main, Germany
- Frankfurt Institute for Advanced Studies (FIAS), Frankfurt/Main, Germany
- * E-mail: (A.V.); (H.C.)
| | - Felix Effenberger
- Ernst Strüngmann Institute (ESI) for Neuroscience in Cooperation with Max Planck Society, Frankfurt/Main, Germany
- Frankfurt Institute for Advanced Studies (FIAS), Frankfurt/Main, Germany
| | - Julia Muellerleile
- Institute of Clinical Neuroanatomy, Goethe University Frankfurt/Main, Germany
| | - Hermann Cuntz
- Ernst Strüngmann Institute (ESI) for Neuroscience in Cooperation with Max Planck Society, Frankfurt/Main, Germany
- Frankfurt Institute for Advanced Studies (FIAS), Frankfurt/Main, Germany
- * E-mail: (A.V.); (H.C.)
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37
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Poznanski RR, Cacha LA, Al-Wesabi YMS, Ali J, Bahadoran M, Yupapin PP, Yunus J. Solitonic conduction of electrotonic signals in neuronal branchlets with polarized microstructure. Sci Rep 2017; 7:2746. [PMID: 28566682 PMCID: PMC5451471 DOI: 10.1038/s41598-017-01849-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 04/07/2017] [Indexed: 11/25/2022] Open
Abstract
A model of solitonic conduction in neuronal branchlets with microstructure is presented. The application of cable theory to neurons with microstructure results in a nonlinear cable equation that is solved using a direct method to obtain analytical approximations of traveling wave solutions. It is shown that a linear superposition of two oppositely directed traveling waves demonstrate solitonic interaction: colliding waves can penetrate through each other, and continue fully intact as the exact pulses that entered the collision. These findings indicate that microstructure when polarized can sustain solitary waves that propagate at a constant velocity without attenuation or distortion in the absence of synaptic transmission. Solitonic conduction in a neuronal branchlet arising from polarizability of its microstructure is a novel signaling mode of electrotonic signals in thin processes (<0.5 μm diameter).
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Affiliation(s)
- R R Poznanski
- Faculty of Biosciences and Medical Engineering, Universiti Teknologi Malaysia, 81310, Johor Bahru, Johor, Malaysia.
| | - L A Cacha
- Laser Centre, IBNU SINA ISIR, Universiti Teknologi Malaysia, 81310, Johor Bahru, Johor, Malaysia
| | - Y M S Al-Wesabi
- Faculty of Biosciences and Medical Engineering, Universiti Teknologi Malaysia, 81310, Johor Bahru, Johor, Malaysia
| | - J Ali
- Laser Centre, IBNU SINA ISIR, Universiti Teknologi Malaysia, 81310, Johor Bahru, Johor, Malaysia
- Faculty of Science, Universiti Teknologi Malaysia, 81310, Johor Bahru, Johor, Malaysia
| | - M Bahadoran
- Department of Physics, Shiraz University of Technology, Shiraz, 313-71555, Iran
| | - P P Yupapin
- Department for Management of Science and Technology Development, Ton Duc Thang University, Ho Chi Minh City, District 7, Vietnam
- Faculty of Electrical & Electronics Engineering, Ton Duc Thang University, Ho Chi Minh City, District 7, Vietnam
| | - J Yunus
- Faculty of Biosciences and Medical Engineering, Universiti Teknologi Malaysia, 81310, Johor Bahru, Johor, Malaysia
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Song LM, Wang XM, Huang JP, Zhu F, Jiang X, Zhang SG, Ban LP. Ultrastructure and morphology of antennal sensilla of the adult diving beetle Cybister japonicus Sharp. PLoS One 2017; 12:e0174643. [PMID: 28358865 PMCID: PMC5373609 DOI: 10.1371/journal.pone.0174643] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2016] [Accepted: 03/13/2017] [Indexed: 11/18/2022] Open
Abstract
The morphology and distribution of the antennal sensilla of adult diving beetle Cybister japonicus Sharp (Dytiscidae, Coleoptera), have been examined. Five types of sensilla on the antennae were identified by scanning electron microscope (SEM) and transmission electron microscope (TEM). Sensilla placodea and elongated s. placodea are the most abundant types of sensilla, distributing only on the flagellum. Both these types of sensilla carry multiple pore systems with a typical function as chemoreceptors. Three types of s. coeloconica (Type I–III) were also identified, with the characterization of the pit-in-pit style, and carrying pegs externally different from each other. Our data indicated that both type I and type II of s. coleconica contain two bipolar neurons, while the type III of s. coleconica contains three dendrites in the peg. Two sensory dendrites in the former two sensilla are tightly embedded inside the dendrite sheath, with no space left for sensilla lymph. There are no specific morphological differences in the antennal sensilla observed between males and females, except that the males have longer antennae and more sensilla than the females.
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Affiliation(s)
- Li-Mei Song
- Department of Grassland Science, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Xue-Min Wang
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Jian-Ping Huang
- Department of Grassland Science, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Fang Zhu
- Department of Entomology, Washington State University, Pullman, Washington, United States of America
| | - Xiang Jiang
- Huangpu Entry-Exit Inspection and Quarantine Bureau, Guangdong, China
| | - Shan-Gan Zhang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Li-Ping Ban
- Department of Grassland Science, College of Animal Science and Technology, China Agricultural University, Beijing, China
- * E-mail:
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Yeh TY, Tseng GF, Tseng CY, Huang YH, Liu PH. Effects of epidural compression on stellate neurons and thalamocortical afferent fibers in the rat primary somatosensory cortex. Acta Neurobiol Exp (Wars) 2017; 77:1-17. [PMID: 28379212 DOI: 10.21307/ane-2017-032] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A number of neurological disorders such as epidural hematoma can cause compression of cerebral cortex. We here tested the hypothesis that sustained compression of primary somatosensory cortex may affect stellate neurons and thalamocortical afferent (TCA) fibers. A rat model with barrel cortex subjected to bead epidural compression was used. Golgi-Cox staining analyses showed the shrinkage of dendritic arbors and the stripping of dendritic spines of stellate neurons for at least 3 months post-lesion. Anterograde tracing analyses exhibited a progressive decline of TCA fiber density in barrel field for 6 months post-lesion. Due to the abrupt decrease of TCA fiber density at 3 days after compression, we further used electron microscopy to investigate the ultrastructure of TCA fibers at this time. Some TCA fiber terminal profiles with dissolved or darkened mitochondria and fewer synaptic vesicles were distorted and broken. Furthermore, the disruption of mitochondria and myelin sheath was observed in some myelinated TCA fibers. In addition, expressions of oxidative markers 3-nitrotyrosine and 4-hydroxynonenal were elevated in barrel field post-lesion. Treatment of antioxidant ascorbic acid or apocynin was able to reverse the increase of oxidative stress and the decline of TCA fiber density, rather than the shrinkage of dendrites and the stripping of dendritic spines of stellate neurons post-lesion. Together, these results indicate that sustained epidural compression of primary somatosensory cortex affects the TCA fibers and the dendrites of stellate neurons for a prolonged period. In addition, oxidative stress is responsible for the reduction of TCA fiber density in barrels rather than the shrinkage of dendrites and the stripping of dendritic spines of stellate neurons.
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Affiliation(s)
- Tzu-Yin Yeh
- Institute of Medical Sciences, Tzu Chi University, Hualien, Taiwan
| | - Guo-Fang Tseng
- Department of Anatomy, Tzu Chi University, Hualien, Taiwan, Institute of Physiological and Anatomical Medicine, Tzu Chi University, Hualien, Taiwan
| | - Chi-Yu Tseng
- Department of Neurology, Taichung Tzu Chi Hospital, Taichung, Taiwan
| | - Yung-Hsin Huang
- Institute of Physiological and Anatomical Medicine, Tzu Chi University, Hualien, Taiwan
| | - Pei-Hsin Liu
- Institute of Medical Sciences, Tzu Chi University, Hualien, Taiwan, Department of Anatomy, Tzu Chi University, Hualien, Taiwan, Institute of Physiological and Anatomical Medicine, Tzu Chi University, Hualien, Taiwan,
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Morozov YM, Datta D, Paspalas CD, Arnsten AFT. Ultrastructural evidence for impaired mitochondrial fission in the aged rhesus monkey dorsolateral prefrontal cortex. Neurobiol Aging 2016; 51:9-18. [PMID: 28027494 DOI: 10.1016/j.neurobiolaging.2016.12.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Revised: 11/30/2016] [Accepted: 12/01/2016] [Indexed: 11/19/2022]
Abstract
Dorsolateral prefrontal cortex mediates high-order cognitive functions that are impaired early in the aging process in monkeys and humans. Here, we report pronounced changes in mitochondrial morphology in dendrites of dorsolateral prefrontal cortex neurons from aged rhesus macaques. Electron microscopy paired with 3D reconstruction from serial sections revealed an age-related increase in mitochondria with thin segments that intermingled with enlarged ones, the 'mitochondria-on-a-string' phenotype, similar to those recently reported in patients with Alzheimer's disease. The thin mitochondrial segments were associated with endoplasmic reticulum cisterns, and the mitochondrial proteins Fis1 and Drp1, all of which initiate mitochondrial fission. These data suggest that the 'mitochondria-on-a-string' phenotype may reflect malfunction in mitochondrial dynamics, whereby fission is initiated, but the process is incomplete due to malfunction of subsequent step(s). Thus, aged rhesus monkeys may be particularly helpful in exploring the age-related changes that render higher cortical circuits so vulnerable to degeneration.
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Affiliation(s)
- Yury M Morozov
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA.
| | - Dibyadeep Datta
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA
| | | | - Amy F T Arnsten
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA.
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Behrens C, Schubert T, Haverkamp S, Euler T, Berens P. Connectivity map of bipolar cells and photoreceptors in the mouse retina. eLife 2016; 5:e20041. [PMID: 27885985 PMCID: PMC5148610 DOI: 10.7554/elife.20041] [Citation(s) in RCA: 103] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Accepted: 11/21/2016] [Indexed: 01/09/2023] Open
Abstract
In the mouse retina, three different types of photoreceptors provide input to 14 bipolar cell (BC) types. Classically, most BC types are thought to contact all cones within their dendritic field; ON-BCs would contact cones exclusively via so-called invaginating synapses, while OFF-BCs would form basal synapses. By mining publically available electron microscopy data, we discovered interesting violations of these rules of outer retinal connectivity: ON-BC type X contacted only ~20% of the cones in its dendritic field and made mostly atypical non-invaginating contacts. Types 5T, 5O and 8 also contacted fewer cones than expected. In addition, we found that rod BCs received input from cones, providing anatomical evidence that rod and cone pathways are interconnected in both directions. This suggests that the organization of the outer plexiform layer is more complex than classically thought.
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Affiliation(s)
- Christian Behrens
- Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
- Center for Integrative Neuroscience, University of Tübingen, Tübingen, Germany
- Bernstein Center for Computational Neuroscience, University of Tübingen, Tübingen, Germany
- Graduate Training Center for Neuroscience, International Max Planck Research School, University of Tübingen, Tübingen, Germany
| | - Timm Schubert
- Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
- Center for Integrative Neuroscience, University of Tübingen, Tübingen, Germany
| | - Silke Haverkamp
- Institute of Cellular and Molecular Anatomy, Goethe-University Frankfurt, Frankfurt, Germany
| | - Thomas Euler
- Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
- Center for Integrative Neuroscience, University of Tübingen, Tübingen, Germany
- Bernstein Center for Computational Neuroscience, University of Tübingen, Tübingen, Germany
| | - Philipp Berens
- Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
- Center for Integrative Neuroscience, University of Tübingen, Tübingen, Germany
- Bernstein Center for Computational Neuroscience, University of Tübingen, Tübingen, Germany
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Szalay G, Judák L, Katona G, Ócsai K, Juhász G, Veress M, Szadai Z, Fehér A, Tompa T, Chiovini B, Maák P, Rózsa B. Fast 3D Imaging of Spine, Dendritic, and Neuronal Assemblies in Behaving Animals. Neuron 2016; 92:723-738. [PMID: 27773582 PMCID: PMC5167293 DOI: 10.1016/j.neuron.2016.10.002] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2015] [Revised: 07/19/2016] [Accepted: 09/20/2016] [Indexed: 11/19/2022]
Abstract
Understanding neural computation requires methods such as 3D acousto-optical (AO) scanning that can simultaneously read out neural activity on both the somatic and dendritic scales. AO point scanning can increase measurement speed and signal-to-noise ratio (SNR) by several orders of magnitude, but high optical resolution requires long point-to-point switching time, which limits imaging capability. Here we present a novel technology, 3D DRIFT AO scanning, which can extend each scanning point to small 3D lines, surfaces, or volume elements for flexible and fast imaging of complex structures simultaneously in multiple locations. Our method was demonstrated by fast 3D recording of over 150 dendritic spines with 3D lines, over 100 somata with squares and cubes, or multiple spiny dendritic segments with surface and volume elements, including in behaving animals. Finally, a 4-fold improvement in total excitation efficiency resulted in about 500 × 500 × 650 μm scanning volume with genetically encoded calcium indicators (GECIs).
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Affiliation(s)
- Gergely Szalay
- Laboratory of 3D Functional Network and Dendritic Imaging, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest 1083, Hungary
| | - Linda Judák
- Laboratory of 3D Functional Network and Dendritic Imaging, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest 1083, Hungary
| | - Gergely Katona
- Laboratory of 3D Functional Network and Dendritic Imaging, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest 1083, Hungary; MTA-PPKE ITK-NAP B-2p Measurement Technology Group, Faculty of Information Technology, Pázmány Péter Catholic University, Budapest 1083, Hungary
| | - Katalin Ócsai
- MTA-PPKE ITK-NAP B-2p Measurement Technology Group, Faculty of Information Technology, Pázmány Péter Catholic University, Budapest 1083, Hungary
| | - Gábor Juhász
- Laboratory of 3D Functional Network and Dendritic Imaging, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest 1083, Hungary; MTA-PPKE ITK-NAP B-2p Measurement Technology Group, Faculty of Information Technology, Pázmány Péter Catholic University, Budapest 1083, Hungary
| | - Máté Veress
- Department of Atomic Physics, Budapest University of Technology and Economics, Budapest 1111, Hungary
| | - Zoltán Szadai
- Laboratory of 3D Functional Network and Dendritic Imaging, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest 1083, Hungary; Two-Photon Laboratory, Faculty of Information Technology, Pázmány Péter Catholic University, Budapest 1083, Hungary
| | - András Fehér
- Department of Atomic Physics, Budapest University of Technology and Economics, Budapest 1111, Hungary
| | - Tamás Tompa
- Laboratory of 3D Functional Network and Dendritic Imaging, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest 1083, Hungary; Two-Photon Laboratory, Faculty of Information Technology, Pázmány Péter Catholic University, Budapest 1083, Hungary
| | - Balázs Chiovini
- Laboratory of 3D Functional Network and Dendritic Imaging, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest 1083, Hungary; Two-Photon Laboratory, Faculty of Information Technology, Pázmány Péter Catholic University, Budapest 1083, Hungary
| | - Pál Maák
- Department of Atomic Physics, Budapest University of Technology and Economics, Budapest 1111, Hungary
| | - Balázs Rózsa
- Laboratory of 3D Functional Network and Dendritic Imaging, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest 1083, Hungary; Two-Photon Laboratory, Faculty of Information Technology, Pázmány Péter Catholic University, Budapest 1083, Hungary.
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Adanina VO, Vesselkin NP. [SYNAPTIC AND ELECTROTONIC CONTACTS ON THE PRIMARY AFFERENT AXONS OF THE SPINAL CORD IN THE LAMPREY LAMPETRA FLUVIATILIS]. Zh Evol Biokhim Fiziol 2016; 52:354-361. [PMID: 30695338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Distribution of GABA and glycine immunoreactivity was studied in synapses on primary afferent axons of the spinal cord in the lamprey Lampetrafluviatilis by double labeling technique. Approximately 25 % of synapses on afferent axons revealed immunoreactivity to GABA and more than 70 % were im- munoreactive to both neurotransmitters. As in other vertebrates, axo-axonal contacts represented three-component synaptic complexes, the so-called triades, where the immunoreactive terminal was in sy- naptic contact both with the afferent axon and the dendrite contacting with this afferent. Contact zones with membrane specializations of gap junction type were found between adjacent afferents that suggests the presence of electrotonic interaction between afferents which serves, evidently, for synchronization of afferent flow and presents a structural base for a mechanism of fast interneuronal communication of func- tionally uniform neurons which is an important element in organization of coordinated locomotor acts. Besides, our studies provide evidence that afferent-afferent interaction may be mediated not only electro- tonically but also with the aid of chemical synapses. This fact gives grounds to suppose that depolariza- tion of primary afferents, produced by glutamate, occurs not only through autoreception mechanism but also by its direct action on the membrane of an afferent axon.
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Miyamoto A, Wake H, Ishikawa AW, Eto K, Shibata K, Murakoshi H, Koizumi S, Moorhouse AJ, Yoshimura Y, Nabekura J. Microglia contact induces synapse formation in developing somatosensory cortex. Nat Commun 2016; 7:12540. [PMID: 27558646 PMCID: PMC5007295 DOI: 10.1038/ncomms12540] [Citation(s) in RCA: 416] [Impact Index Per Article: 52.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Accepted: 07/12/2016] [Indexed: 01/17/2023] Open
Abstract
Microglia are the immune cells of the central nervous system that play important roles in brain pathologies. Microglia also help shape neuronal circuits during development, via phagocytosing weak synapses and regulating neurogenesis. Using in vivo multiphoton imaging of layer 2/3 pyramidal neurons in the developing somatosensory cortex, we demonstrate here that microglial contact with dendrites directly induces filopodia formation. This filopodia formation occurs only around postnatal day 8-10, a period of intense synaptogenesis and when microglia have an activated phenotype. Filopodia formation is preceded by contact-induced Ca(2+) transients and actin accumulation. Inhibition of microglia by genetic ablation decreases subsequent spine density, functional excitatory synapses and reduces the relative connectivity from layer 4 neurons. Our data provide the direct demonstration of microglial-induced spine formation and provide further insights into immune system regulation of neuronal circuit development, with potential implications for developmental disorders of immune and brain dysfunction.
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Affiliation(s)
- Akiko Miyamoto
- Division of Homeostatic Development, National Institute for Physiological Sciences, Okazaki 444-8585, Japan
- Core Research for Evolutional Science and Technology, Japan Agency for Medical Research and Development, Tokyo 100-0004, Japan
| | - Hiroaki Wake
- Division of Homeostatic Development, National Institute for Physiological Sciences, Okazaki 444-8585, Japan
- Core Research for Evolutional Science and Technology, Japan Agency for Medical Research and Development, Tokyo 100-0004, Japan
- Department of Physiological Sciences, The Graduate School for Advanced Study, Hayama 240-0193, Japan
- Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, Saitama 102-0076, Japan
| | - Ayako Wendy Ishikawa
- Department of Physiological Sciences, The Graduate School for Advanced Study, Hayama 240-0193, Japan
- Division of Visual Information Processing, National Institute for Physiological Sciences, Okazaki 444-8585, Japan
| | - Kei Eto
- Division of Homeostatic Development, National Institute for Physiological Sciences, Okazaki 444-8585, Japan
- Core Research for Evolutional Science and Technology, Japan Agency for Medical Research and Development, Tokyo 100-0004, Japan
- Department of Physiological Sciences, The Graduate School for Advanced Study, Hayama 240-0193, Japan
| | - Keisuke Shibata
- Core Research for Evolutional Science and Technology, Japan Agency for Medical Research and Development, Tokyo 100-0004, Japan
- Department of Pharmacology, Graduated School of Medical and Engineering, Yamanashi University, Chuo 409-3898, Japan
| | - Hideji Murakoshi
- Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, Saitama 102-0076, Japan
- Section of Multiphoton Neuroimaging, National Institute for Physiological Sciences, Okazaki 444-8585, Japan
| | - Schuichi Koizumi
- Core Research for Evolutional Science and Technology, Japan Agency for Medical Research and Development, Tokyo 100-0004, Japan
- Department of Pharmacology, Graduated School of Medical and Engineering, Yamanashi University, Chuo 409-3898, Japan
| | - Andrew J. Moorhouse
- School of Medical Sciences, The University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Yumiko Yoshimura
- Department of Physiological Sciences, The Graduate School for Advanced Study, Hayama 240-0193, Japan
- Division of Visual Information Processing, National Institute for Physiological Sciences, Okazaki 444-8585, Japan
| | - Junichi Nabekura
- Division of Homeostatic Development, National Institute for Physiological Sciences, Okazaki 444-8585, Japan
- Core Research for Evolutional Science and Technology, Japan Agency for Medical Research and Development, Tokyo 100-0004, Japan
- Department of Physiological Sciences, The Graduate School for Advanced Study, Hayama 240-0193, Japan
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Karube F, Sári K, Kisvárday ZF. Axon topography of layer 6 spiny cells to orientation map in the primary visual cortex of the cat (area 18). Brain Struct Funct 2016; 222:1401-1426. [PMID: 27539451 PMCID: PMC5368233 DOI: 10.1007/s00429-016-1284-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 08/02/2016] [Indexed: 11/28/2022]
Abstract
To uncover the functional topography of layer 6 neurons, optical imaging was combined with three-dimensional neuronal reconstruction. Apical dendrite morphology of 23 neurons revealed three distinct types. Type Aa possessed a short apical dendrite with many oblique branches, Type Ab was characterized by a short and less branched apical dendrite, whereas Type B had a long apical dendrite with tufts in layer 2. Each type had a similar number of boutons, yet their spatial distribution differed from each other in both radial and horizontal extent. Boutons of Type Aa and Ab were almost restricted to the column of the parent soma with a laminar preference to layer 4 and 5/6, respectively. Only Type B contributed to long horizontal connections (up to 1.5 mm) mostly in deep layers. For all types, bouton distribution on orientation map showed an almost equal occurrence at iso- (52.6 ± 18.8 %) and non-iso-orientation (oblique, 27.7 ± 14.9 % and cross-orientation 19.7 ± 10.9 %) sites. Spatial convergence of axons of nearby layer 6 spiny neurons depended on soma separation of the parent cells, but only weakly on orientation preference, contrary to orientation dependence of converging axons of layer 4 spiny cells. The results show that layer 6 connections have only a weak dependence on orientation preference compared with those of layers 2/3 (Buzás et al., J Comp Neurol 499:861–881, 2006) and 4 (Karube and Kisvárday, Cereb Cortex 21:1443–1458, 2011).
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Affiliation(s)
- Fuyuki Karube
- Laboratory for Cortical Systems Neuroscience, Department of Anatomy, Histology and Embryology, University of Debrecen, Debrecen, 4032, Hungary
- Graduate School of Brain Science, Doshisha University, Tataramiyakodani 1-3, Kyotanabe, Kyoto, 610-0394, Japan
| | - Katalin Sári
- Laboratory for Cortical Systems Neuroscience, Department of Anatomy, Histology and Embryology, University of Debrecen, Debrecen, 4032, Hungary
- Department of Neurosciences Fondamentales, Centre Médical Universitaire, Rue Michel-Servet 1, 4, 1211, Geneva, Switzerland
| | - Zoltán F Kisvárday
- Laboratory for Cortical Systems Neuroscience, Department of Anatomy, Histology and Embryology, University of Debrecen, Debrecen, 4032, Hungary.
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Riew TR, Shin YJ, Kim HL, Cho JM, Pak HJ, Lee MY. Spatiotemporal Progression of Microcalcification in the Hippocampal CA1 Region following Transient Forebrain Ischemia in Rats: An Ultrastructural Study. PLoS One 2016; 11:e0159229. [PMID: 27414398 PMCID: PMC4945069 DOI: 10.1371/journal.pone.0159229] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 06/29/2016] [Indexed: 11/19/2022] Open
Abstract
Calcification in areas of neuronal degeneration is a common finding in several neuropathological disorders including ischemic insults. Here, we performed a detailed examination of the onset and spatiotemporal profile of calcification in the CA1 region of the hippocampus, where neuronal death has been observed after transient forebrain ischemia. Histopathological examinations showed very little alizarin red staining in the CA1 pyramidal cell layer until day 28 after reperfusion, while prominent alizarin red staining was detected in CA1 dendritic subfields, particularly in the stratum radiatum, by 14 days after reperfusion. Electron microscopy using the osmium/potassium dichromate method and electron probe microanalysis revealed selective calcium deposits within the mitochondria of degenerating dendrites at as early as 7 days after reperfusion, with subsequent complete mineralization occurring throughout the dendrites, which then coalesced to form larger mineral conglomerates with the adjacent calcifying neurites by 14 days after reperfusion. Large calcifying deposits were frequently observed at 28 days after reperfusion, when they were closely associated with or completely engulfed by astrocytes. In contrast, no prominent calcification was observed in the somata of CA1 pyramidal neurons showing the characteristic features of necrotic cell death after ischemia, although what appeared to be calcified mitochondria were noted in some degenerated neurons that became dark and condensed. Thus, our data indicate that intrahippocampal calcification after ischemic insults initially occurs within the mitochondria of degenerating dendrites, which leads to the extensive calcification that is associated with ischemic injuries. These findings suggest that in degenerating neurons, the calcified mitochondria in the dendrites, rather than in the somata, may serve as the nidus for further calcium precipitation in the ischemic hippocampus.
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Affiliation(s)
- Tae-Ryong Riew
- Department of Anatomy, Catholic Neuroscience Institute, Cell Death Disease Research Center, College of Medicine, The Catholic University of Korea, 137-701, Seoul, Korea
| | - Yoo-Jin Shin
- Department of Anatomy, Catholic Neuroscience Institute, Cell Death Disease Research Center, College of Medicine, The Catholic University of Korea, 137-701, Seoul, Korea
| | - Hong Lim Kim
- Integrative Research Support Center, Laboratory of Electron Microscope, College of Medicine, The Catholic University of Korea, Seoul, Korea, 137-701, Seoul, Korea
| | - Jeong Min Cho
- Department of Anatomy, Catholic Neuroscience Institute, Cell Death Disease Research Center, College of Medicine, The Catholic University of Korea, 137-701, Seoul, Korea
| | - Ha-Jin Pak
- Department of Anatomy, Catholic Neuroscience Institute, Cell Death Disease Research Center, College of Medicine, The Catholic University of Korea, 137-701, Seoul, Korea
| | - Mun-Yong Lee
- Department of Anatomy, Catholic Neuroscience Institute, Cell Death Disease Research Center, College of Medicine, The Catholic University of Korea, 137-701, Seoul, Korea
- * E-mail:
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Abstract
One of the fundamental features of the visual system is the segregation of neural circuits that process increments and decrements of luminance into ON and OFF pathways. In mature retina, the dendrites of retinal ganglion cells (RGCs) in the inner plexiform layer (IPL) of retina are separated into ON or OFF sublaminaspecific stratification. At an early developmental stage, however, the dendrites of most RGCs are ramified throughout the IPL. The maturation of RGC ON/OFF dendritic stratification requires neural activities mediated by afferent inputs from bipolar and amacrine cells. The synchronized spontaneous burst activities in early postnatal developing retina regulate RGC dendritic filopodial movements and the maintenance or elimination of dendritic processes. After eye opening, visual experience further remodels and consolidates the retinal neural circuit into mature forms. Several neurotransmitter systems, including glutamatergic, acetylcholinergic, GAB Aergic, and glycinergic systems, might act together to modulate the RGC dendritic refinement. In addition, both the bipolar cells and cholinergic amacrine cells may provide laminar cues for the maturation of RGC dendritic stratification.
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Affiliation(s)
- Hongping Xu
- Department of Ophthalmology and Visual Science, Yale University School of Medicine, New Haven, Connecticut 06520, USA
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Shen HC, Wei JY, Chu SY, Chung PC, Hsu TC, Yu HH. Morphogenetic Studies of the Drosophila DA1 Ventral Olfactory Projection Neuron. PLoS One 2016; 11:e0155384. [PMID: 27163287 PMCID: PMC4862648 DOI: 10.1371/journal.pone.0155384] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 04/27/2016] [Indexed: 01/04/2023] Open
Abstract
In the Drosophila olfactory system, odorant information is sensed by olfactory sensory neurons and relayed from the primary olfactory center, the antennal lobe (AL), to higher olfactory centers via olfactory projection neurons (PNs). A major portion of the AL is constituted with dendrites of four groups of PNs, anterodorsal PNs (adPNs), lateral PNs (lPNs), lateroventral PNs (lvPNs) and ventral PNs (vPNs). Previous studies have been focused on the development and function of adPNs and lPNs, while the investigation on those of lvPNs and vPNs received less attention. Here, we study the molecular and cellular mechanisms underlying the morphogenesis of a putative male-pheromone responding vPN, the DA1 vPN. Using an intersection strategy to remove background neurons labeled within a DA1 vPN-containing GAL4 line, we depicted morphological changes of the DA1 vPN that occurs at the pupal stage. We then conducted a pilot screen using RNA interference knock-down approach to identify cell surface molecules, including Down syndrome cell adhesion molecule 1 and Semaphorin-1a, that might play essential roles for the DA1 vPN morphogenesis. Taken together, by revealing molecular and cellular basis of the DA1 vPN morphogenesis, we should provide insights into future comprehension of how vPNs are assembled into the olfactory neural circuitry.
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Affiliation(s)
- Hung-Chang Shen
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan
| | - Jia-Yi Wei
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Sao-Yu Chu
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Pei-Chi Chung
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Tsai-Chi Hsu
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Hung-Hsiang Yu
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan
- * E-mail:
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Li S, Mitchell J, Briggs DJ, Young JK, Long SS, Fuerst PG. Morphological Diversity of the Rod Spherule: A Study of Serially Reconstructed Electron Micrographs. PLoS One 2016; 11:e0150024. [PMID: 26930660 PMCID: PMC4773090 DOI: 10.1371/journal.pone.0150024] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 02/08/2016] [Indexed: 11/25/2022] Open
Abstract
Purpose Rod spherules are the site of the first synaptic contact in the retina’s rod pathway, linking rods to horizontal and bipolar cells. Rod spherules have been described and characterized through electron micrograph (EM) and other studies, but their morphological diversity related to retinal circuitry and their intracellular structures have not been quantified. Most rod spherules are connected to their soma by an axon, but spherules of rods on the surface of the Mus musculus outer plexiform layer often lack an axon and have a spherule structure that is morphologically distinct from rod spherules connected to their soma by an axon. Retraction of the rod axon and spherule is often observed in disease processes and aging, and the retracted rod spherule superficially resembles rod spherules lacking an axon. We hypothesized that retracted spherules take on an axonless spherule morphology, which may be easier to maintain in a diseased state. To test our hypothesis, we quantified the spatial organization and subcellular structures of rod spherules with and without axons. We then compared them to the retracted spherules in a disease model, mice that overexpress Dscam (Down syndrome cell adhesion molecule), to gain a better understanding of the rod synapse in health and disease. Methods We reconstructed serial EM images of wild type and DscamGoF (gain of function) rod spherules at a resolution of 7 nm in the X-Y axis and 60 nm in the Z axis. Rod spherules with and without axons, and retracted spherules in the DscamGoF retina, were reconstructed. The rod spherule intracellular organelles, the invaginating dendrites of rod bipolar cells and horizontal cell axon tips were also reconstructed for statistical analysis. Results Stereotypical rod (R1) spherules occupy the outer two-thirds of the outer plexiform layer (OPL), where they present as spherical terminals with large mitochondria. This spherule group is highly uniform and composed more than 90% of the rod spherule population. Rod spherules lacking an axon (R2) were also described and characterized. This rod spherule group consists of a specific spatial organization that is strictly located at the apical OPL-facing layer of the Outer Nuclear Layer (ONL). The R2 spherule displays a large bowl-shaped synaptic terminal that hugs the rod soma. Retracted spherules in the DscamGoF retina were also reconstructed to test if they are structurally similar to R2 spherules. The misplaced rod spherules in DscamGoF have a gross morphology that is similar to R2 spherules but have significant disruption in internal synapse organization. Conclusion We described a morphological diversity within Mus musculus rod spherules. This diversity is correlated with rod location in the ONL and contributes to the intracellular differences within spherules. Analysis of the DscamGoF retina indicated that their R2 spherules are not significantly different than wild type R2 spherules, but that their retracted rod spherules have abnormal synaptic organization.
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Affiliation(s)
- Shuai Li
- University of Idaho, Department of Biological Sciences, Moscow, Idaho, 83844, United States of America
| | - Joe Mitchell
- North Idaho College, Natural Sciences Division, Coeur d’Alene, Idaho, 83814, United States of America
| | - Deidrie J. Briggs
- University of Idaho, Department of Biological Sciences, Moscow, Idaho, 83844, United States of America
| | - Jaime K. Young
- University of Idaho, Department of Biological Sciences, Moscow, Idaho, 83844, United States of America
| | - Samuel S. Long
- Lewis-Clark State College, Department of Computer Sciences, Lewiston, Idaho, 83501, United States of America
| | - Peter G. Fuerst
- University of Idaho, Department of Biological Sciences, Moscow, Idaho, 83844, United States of America
- WWAMI Medical Education Program, Moscow, Idaho, 83844, United States of America
- * E-mail:
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Swanger SA, Vance KM, Pare JF, Sotty F, Fog K, Smith Y, Traynelis SF. NMDA Receptors Containing the GluN2D Subunit Control Neuronal Function in the Subthalamic Nucleus. J Neurosci 2015; 35:15971-83. [PMID: 26631477 PMCID: PMC4666920 DOI: 10.1523/jneurosci.1702-15.2015] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Revised: 10/20/2015] [Accepted: 10/29/2015] [Indexed: 01/25/2023] Open
Abstract
The GluN2D subunit of the NMDA receptor is prominently expressed in the basal ganglia and associated brainstem nuclei, including the subthalamic nucleus (STN), globus pallidus, striatum, and substantia nigra. However, little is known about how GluN2D-containing NMDA receptors contribute to synaptic activity in these regions. Using Western blotting of STN tissue punches, we demonstrated that GluN2D is expressed in the rat STN throughout development [age postnatal day 7 (P7)-P60] and in the adult (age P120). Immunoelectron microscopy of the adult rat brain showed that GluN2D is predominantly expressed in dendrites, unmyelinated axons, and axon terminals within the STN. Using subunit-selective allosteric modulators of NMDA receptors (TCN-201, ifenprodil, CIQ, and DQP-1105), we provide evidence that receptors containing the GluN2B and GluN2D subunits mediate responses to exogenously applied NMDA and glycine, as well as synaptic NMDA receptor activation in the STN of rat brain slices. EPSCs in the STN were mediated primarily by AMPA and NMDA receptors and GluN2D-containing NMDA receptors controlled the slow deactivation time course of EPSCs in the STN. In vivo recordings from the STN of anesthetized adult rats demonstrated that the spike firing rate was increased by the GluN2C/D potentiator CIQ and decreased by the GluN2C/D antagonist DQP-1105, suggesting that NMDA receptor activity can influence STN output. These data indicate that the GluN2B and GluN2D NMDA receptor subunits contribute to synaptic activity in the STN and may represent potential therapeutic targets for modulating subthalamic neuron activity in neurological disorders such as Parkinson's disease.
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Affiliation(s)
| | | | - Jean-François Pare
- Yerkes National Primate Research Center and Morris K. Udall Center of Excellence for Parkinson's Disease Research, Emory University, Atlanta, Georgia 30329, and
| | - Florence Sotty
- H. Lundbeck A/S, Division of Neurodegeneration and Biologics, Ottiliavej 9, DK-2500 Valby, Denmark
| | - Karina Fog
- H. Lundbeck A/S, Division of Neurodegeneration and Biologics, Ottiliavej 9, DK-2500 Valby, Denmark
| | - Yoland Smith
- Department of Neurology, Emory University School of Medicine, Atlanta, Georgia 30322, Yerkes National Primate Research Center and Morris K. Udall Center of Excellence for Parkinson's Disease Research, Emory University, Atlanta, Georgia 30329, and
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