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Zhu YJ, Deng CY, Fan L, Wang YQ, Zhou H, Xu HT. Combinatorial expression of γ-protocadherins regulates synaptic connectivity in the mouse neocortex. eLife 2024; 12:RP89532. [PMID: 38470230 DOI: 10.7554/elife.89532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/13/2024] Open
Abstract
In the process of synaptic formation, neurons must not only adhere to specific principles when selecting synaptic partners but also possess mechanisms to avoid undesirable connections. Yet, the strategies employed to prevent unwarranted associations have remained largely unknown. In our study, we have identified the pivotal role of combinatorial clustered protocadherin gamma (γ-PCDH) expression in orchestrating synaptic connectivity in the mouse neocortex. Through 5' end single-cell sequencing, we unveiled the intricate combinatorial expression patterns of γ-PCDH variable isoforms within neocortical neurons. Furthermore, our whole-cell patch-clamp recordings demonstrated that as the similarity in this combinatorial pattern among neurons increased, their synaptic connectivity decreased. Our findings elucidate a sophisticated molecular mechanism governing the construction of neural networks in the mouse neocortex.
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Affiliation(s)
- Yi-Jun Zhu
- Institute of Neuroscience and State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
- Lingang Laboratory, Shanghai Center for Brain Science and Brain-Inspired Intelligence Technology, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Cai-Yun Deng
- Institute of Neuroscience and State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
| | - Liu Fan
- Lingang Laboratory, Shanghai Center for Brain Science and Brain-Inspired Intelligence Technology, Shanghai, China
| | - Ya-Qian Wang
- Lingang Laboratory, Shanghai Center for Brain Science and Brain-Inspired Intelligence Technology, Shanghai, China
| | - Hui Zhou
- Lingang Laboratory, Shanghai Center for Brain Science and Brain-Inspired Intelligence Technology, Shanghai, China
| | - Hua-Tai Xu
- Institute of Neuroscience and State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
- Lingang Laboratory, Shanghai Center for Brain Science and Brain-Inspired Intelligence Technology, Shanghai, China
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2
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Hu G, Chen A, Ye J, Liu Q, Wang J, Fan C, Wang X, Huang M, Dai M, Shi X, Gu Y. A developmental critical period for ocular dominance plasticity of binocular neurons in mouse superior colliculus. Cell Rep 2024; 43:113667. [PMID: 38184852 DOI: 10.1016/j.celrep.2023.113667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 09/29/2023] [Accepted: 12/25/2023] [Indexed: 01/09/2024] Open
Abstract
Detecting visual features in the environment is crucial for animals' survival. The superior colliculus (SC) is implicated in motion detection and processing, whereas how the SC integrates visual inputs from the two eyes remains unclear. Using in vivo electrophysiology, we show that mouse SC contains many binocular neurons that display robust ocular dominance (OD) plasticity in a critical period during early development, which is similar to, but not dependent on, the primary visual cortex. NR2A- and NR2B-containing N-methyl-D-aspartate (NMDA) receptors play an essential role in the regulation of SC plasticity. Blocking NMDA receptors can largely prevent the impairment of predatory hunting caused by monocular deprivation, indicating that maintaining the binocularity of SC neurons is required for efficient hunting behavior. Together, our studies reveal the existence and function of OD plasticity in SC, which broadens our understanding of the development of subcortical visual circuitry relating to motion detection and predatory hunting.
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Affiliation(s)
- Guanglei Hu
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200032, China; School of Life Sciences, Westlake University, Hangzhou 310000, China
| | - Ailin Chen
- Tianjin Eye Hospital, Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin Eye Institute, Clinical College of Ophthalmology, Tianjin Medical University, Tianjin 300020, China
| | - Jingjing Ye
- Tianjin Eye Hospital, Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin Eye Institute, Clinical College of Ophthalmology, Tianjin Medical University, Tianjin 300020, China; Medical College of Optometry and Ophthalmology, Shandong University of Traditional Chinese Medicine, Jinan 250014, China
| | - Qiong Liu
- School of Life Sciences, Westlake University, Hangzhou 310000, China
| | - Jiafeng Wang
- Tianjin Eye Hospital, Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin Eye Institute, Clinical College of Ophthalmology, Tianjin Medical University, Tianjin 300020, China
| | - Cunxiu Fan
- Jiading Branch of Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, 800 Huangjiahuayuan Road, Shanghai 201803, China
| | - Xiaoqing Wang
- Department of Dermatology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China
| | - Mengqi Huang
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Menghan Dai
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Xuefeng Shi
- Tianjin Eye Hospital, Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin Eye Institute, Clinical College of Ophthalmology, Tianjin Medical University, Tianjin 300020, China; Medical College of Optometry and Ophthalmology, Shandong University of Traditional Chinese Medicine, Jinan 250014, China; Institute of Ophthalmology, Nankai University, Tianjin 300020, China.
| | - Yu Gu
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200032, China.
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Irie K, Ohta KI, Ujihara H, Araki C, Honda K, Suzuki S, Warita K, Otabi H, Kumei H, Nakamura S, Koyano K, Miki T, Kusaka T. An enriched environment ameliorates the reduction of parvalbumin-positive interneurons in the medial prefrontal cortex caused by maternal separation early in life. Front Neurosci 2024; 17:1308368. [PMID: 38292903 PMCID: PMC10825025 DOI: 10.3389/fnins.2023.1308368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Accepted: 12/11/2023] [Indexed: 02/01/2024] Open
Abstract
Early child maltreatment, such as child abuse and neglect, is well known to affect the development of social skills. However, the mechanisms by which such an adverse environment interrupts the development of social skills remain unelucidated. Identifying the period and brain regions that are susceptible to adverse environments can lead to appropriate developmental care later in life. We recently reported an excitatory/inhibitory imbalance and low activity during social behavior in the medial prefrontal cortex (mPFC) of the maternal separation (MS) animal model of early life neglect after maturation. Based on these results, in the present study, we investigated how MS disturbs factors related to excitatory and inhibitory neurons in the mPFC until the critical period of mPFC development. Additionally, we evaluated whether the effects of MS could be recovered in an enriched environment after MS exposure. Rat pups were separated from their dams on postnatal days (PDs) 2-20 (twice daily, 3 h each) and compared with the mother-reared control (MRC) group. Gene expression analysis revealed that various factors related to excitatory and inhibitory neurons were transiently disturbed in the mPFC during MS. A similar tendency was found in the sensory cortex; however, decreased parvalbumin (PV) expression persisted until PD 35 only in the mPFC. Moreover, the number of PV+ interneurons decreased in the ventromedial prefrontal cortex (vmPFC) on PD 35 in the MS group. Additionally, perineural net formation surrounding PV+ interneurons, which is an indicator of maturity and critical period closure, was unchanged, indicating that the decreased PV+ interneurons were not simply attributable to developmental delay. This reduction of PV+ interneurons improved to the level observed in the MRC group by the enriched environment from PD 21 after the MS period. These results suggest that an early adverse environment disturbs the development of the mPFC but that these abnormalities allow room for recovery depending on the subsequent environment. Considering that PV+ interneurons in the mPFC play an important role in social skills such as empathy, an early rearing environment is likely a very important factor in the subsequent acquisition of social skills.
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Affiliation(s)
- Kanako Irie
- Department of Anatomy and Neurobiology, Faculty of Medicine, Kagawa University, Kagawa, Japan
- Department of Pediatrics, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Ken-ichi Ohta
- Department of Anatomy and Neurobiology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Hidetoshi Ujihara
- Department of Anatomy and Neurobiology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Chihiro Araki
- Department of Anatomy and Neurobiology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Kodai Honda
- Department of Anatomy and Neurobiology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Shingo Suzuki
- Department of Anatomy and Neurobiology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Katsuhiko Warita
- Department of Veterinary Anatomy, Faculty of Agriculture, Tottori University, Tottori, Japan
| | - Hikari Otabi
- Department of Anatomy and Neurobiology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Haruki Kumei
- Department of Anatomy and Neurobiology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Shinji Nakamura
- Department of Pediatrics, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Kosuke Koyano
- Department of Pediatrics, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Takanori Miki
- Department of Anatomy and Neurobiology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Takashi Kusaka
- Department of Pediatrics, Faculty of Medicine, Kagawa University, Kagawa, Japan
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Wang L, Nakazawa S, Luo W, Sato T, Mizuno H, Iwasato T. Short-Term Dendritic Dynamics of Neonatal Cortical Neurons Revealed by In Vivo Imaging with Improved Spatiotemporal Resolution. eNeuro 2023; 10:ENEURO.0142-23.2023. [PMID: 37890991 PMCID: PMC10630926 DOI: 10.1523/eneuro.0142-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 09/16/2023] [Accepted: 09/19/2023] [Indexed: 10/29/2023] Open
Abstract
Individual neurons in sensory cortices exhibit specific receptive fields based on their dendritic patterns. These dendritic morphologies are established and refined during the neonatal period through activity-dependent plasticity. This process can be visualized using two-photon in vivo time-lapse imaging, but sufficient spatiotemporal resolution is essential. We previously examined dendritic patterning from spiny stellate (SS) neurons, the major type of layer 4 (L4) neurons, in the mouse primary somatosensory cortex (barrel cortex), where mature dendrites display a strong orientation bias toward the barrel center. Longitudinal imaging at 8 h intervals revealed the long-term dynamics by which SS neurons acquire this unique dendritic pattern. However, the spatiotemporal resolution was insufficient to detect the more rapid changes in SS neuron dendrite morphology during the critical neonatal period. In the current study, we imaged neonatal L4 neurons hourly for 8 h and improved the spatial resolution by uniform cell surface labeling. The improved spatiotemporal resolution allowed detection of precise changes in dendrite morphology and revealed aspects of short-term dendritic dynamics unique to the neonatal period. Basal dendrites of barrel cortex L4 neurons were highly dynamic. In particular, both barrel-inner and barrel-outer dendrites (trees and branches) emerged/elongated and disappeared/retracted at similarly high frequencies, suggesting that SS neurons acquire biased dendrite patterns through rapid trial-and-error emergence, elongation, elimination, and retraction of dendritic trees and branches. We also found correlations between morphology and behavior (elongation/retraction) of dendritic tips. Thus, the current study revealed short-term dynamics and related features of cortical neuron dendrites during refinement.
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Affiliation(s)
- Luwei Wang
- Laboratory of Mammalian Neural Circuits, National Institute of Genetics, Mishima 411-8540, Japan
- Graduate Institute for Advanced Studies, SOKENDAI, Mishima 411-8540, Japan
| | - Shingo Nakazawa
- Laboratory of Mammalian Neural Circuits, National Institute of Genetics, Mishima 411-8540, Japan
| | - Wenshu Luo
- Laboratory of Mammalian Neural Circuits, National Institute of Genetics, Mishima 411-8540, Japan
| | - Takuya Sato
- Laboratory of Mammalian Neural Circuits, National Institute of Genetics, Mishima 411-8540, Japan
| | - Hidenobu Mizuno
- International Research Center for Medical Sciences, Kumamoto University, Kumamoto 860-0811, Japan
| | - Takuji Iwasato
- Laboratory of Mammalian Neural Circuits, National Institute of Genetics, Mishima 411-8540, Japan
- Graduate Institute for Advanced Studies, SOKENDAI, Mishima 411-8540, Japan
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5
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Liu B, Li Y, Ren M, Li X. Targeted approaches to delineate neuronal morphology during early development. Front Cell Neurosci 2023; 17:1259360. [PMID: 37854514 PMCID: PMC10579594 DOI: 10.3389/fncel.2023.1259360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Accepted: 09/18/2023] [Indexed: 10/20/2023] Open
Abstract
Understanding the developmental changes that affect neurons is a key step in exploring the assembly and maturation of neural circuits in the brain. For decades, researchers have used a number of labeling techniques to visualize neuronal morphology at different stages of development. However, the efficiency and accuracy of neuronal labeling technologies are limited by the complexity and fragility of neonatal brains. In this review, we illustrate the various labeling techniques utilized for examining the neurogenesis and morphological changes occurring during the early stages of development. We compare the advantages and limitations of each technique from different aspects. Then, we highlight the gaps remaining in our understanding of the structure of neurons in the neonatal mouse brain.
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Affiliation(s)
- Bimin Liu
- State Key Laboratory of Digital Medical Engineering, School of Biomedical Engineering, Hainan University, Haikou, China
- Key Laboratory of Biomedical Engineering of Hainan Province, School of Biomedical Engineering, Hainan University, Haikou, China
| | - Yuxiao Li
- State Key Laboratory of Digital Medical Engineering, School of Biomedical Engineering, Hainan University, Haikou, China
- Key Laboratory of Biomedical Engineering of Hainan Province, School of Biomedical Engineering, Hainan University, Haikou, China
| | - Miao Ren
- State Key Laboratory of Digital Medical Engineering, School of Biomedical Engineering, Hainan University, Haikou, China
- Key Laboratory of Biomedical Engineering of Hainan Province, School of Biomedical Engineering, Hainan University, Haikou, China
| | - Xiangning Li
- State Key Laboratory of Digital Medical Engineering, School of Biomedical Engineering, Hainan University, Haikou, China
- Key Laboratory of Biomedical Engineering of Hainan Province, School of Biomedical Engineering, Hainan University, Haikou, China
- Research Unit of Multimodal Cross Scale Neural Signal Detection and Imaging, Chinese Academy of Medical Sciences, HUST-Suzhou Institute for Brainsmatics, JITRI, Suzhou, China
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6
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Argunsah AÖ, Israely I. Homosynaptic plasticity induction causes heterosynaptic changes at the unstimulated neighbors in an induction pattern and location-specific manner. Front Cell Neurosci 2023; 17:1253446. [PMID: 37829671 PMCID: PMC10564986 DOI: 10.3389/fncel.2023.1253446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 08/24/2023] [Indexed: 10/14/2023] Open
Abstract
Dendritic spines are highly dynamic structures whose structural and functional fluctuations depend on multiple factors. Changes in synaptic strength are not limited to synapses directly involved in specific activity patterns. Unstimulated clusters of neighboring spines in and around the site of stimulation can also undergo alterations in strength. Usually, when plasticity is induced at single dendritic spines with glutamate uncaging, neighboring spines do not show any significant structural fluctuations. Here, using two-photon imaging and glutamate uncaging at single dendritic spines of hippocampal pyramidal neurons, we show that structural modifications at unstimulated neighboring spines occur and are a function of the temporal pattern of the plasticity-inducing stimulus. Further, the relative location of the unstimulated neighbors within the local dendritic segment correlates with the extent of heterosynaptic plasticity that is observed. These findings indicate that naturalistic patterns of activity at single spines can shape plasticity at nearby clusters of synapses, and may play a role in priming local inputs for further modifications.
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Affiliation(s)
- Ali Özgür Argunsah
- Laboratory of Neuronal Circuit Assembly, Brain Research Institute (HiFo), University of Zurich, Zurich, Switzerland
- Department of Molecular Biology and Genetics, Faculty of Engineering and Natural Sciences, Kadir Has University, Istanbul, Türkiye
| | - Inbal Israely
- Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle, WA, United States
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Guillamón-Vivancos T, Vandael D, Torres D, López-Bendito G, Martini FJ. Mesoscale calcium imaging in vivo: evolution and contribution to developmental neuroscience. Front Neurosci 2023; 17:1210199. [PMID: 37592948 PMCID: PMC10427507 DOI: 10.3389/fnins.2023.1210199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Accepted: 07/14/2023] [Indexed: 08/19/2023] Open
Abstract
Calcium imaging is commonly used to visualize neural activity in vivo. In particular, mesoscale calcium imaging provides large fields of view, allowing for the simultaneous interrogation of neuron ensembles across the neuraxis. In the field of Developmental Neuroscience, mesoscopic imaging has recently yielded intriguing results that have shed new light on the ontogenesis of neural circuits from the first stages of life. We summarize here the technical approaches, basic notions for data analysis and the main findings provided by this technique in the last few years, with a focus on brain development in mouse models. As new tools develop to optimize calcium imaging in vivo, basic principles of neural development should be revised from a mesoscale perspective, that is, taking into account widespread activation of neuronal ensembles across the brain. In the future, combining mesoscale imaging of the dorsal surface of the brain with imaging of deep structures would ensure a more complete understanding of the construction of circuits. Moreover, the combination of mesoscale calcium imaging with other tools, like electrophysiology or high-resolution microscopy, will make up for the spatial and temporal limitations of this technique.
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Affiliation(s)
- Teresa Guillamón-Vivancos
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-Consejo Superior de Investigaciones Científicas (UMH-CSIC), Sant Joan d’Alacant, Spain
| | | | | | | | - Francisco J. Martini
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-Consejo Superior de Investigaciones Científicas (UMH-CSIC), Sant Joan d’Alacant, Spain
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8
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Wang M, Yu X. Experience-dependent structural plasticity of pyramidal neurons in the developing sensory cortices. Curr Opin Neurobiol 2023; 81:102724. [PMID: 37068383 DOI: 10.1016/j.conb.2023.102724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 03/16/2023] [Accepted: 03/17/2023] [Indexed: 04/19/2023]
Abstract
Sensory experience regulates the structural and functional wiring of neuronal circuits, during development and throughout adulthood. Here, we review current knowledge of how experience affects structural plasticity of pyramidal neurons in the sensory cortices. We discuss the pros and cons of existing labeling approaches, as well as what structural parameters are most plastic. We further discuss how recent advances in sparse labeling of specific neuronal subtypes, as well as development of techniques that allow fast, high resolution imaging in large fields, would enable future studies to address currently unanswered questions in the field of structural plasticity.
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Affiliation(s)
- Miao Wang
- State Key Laboratory of Membrane Biology, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, and PKU-IDG/McGovern Institute, Peking University, Beijing 100871, China.
| | - Xiang Yu
- State Key Laboratory of Membrane Biology, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, and PKU-IDG/McGovern Institute, Peking University, Beijing 100871, China; Autism Research Center of Peking University Health Science Center, Beijing 100191, China; Chinese Institute for Brain Research, Beijing 102206, China.
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9
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Ashtari M, Cook P, Lipin M, Yu Y, Ying GS, Maguire A, Bennett J, Gee J, Zhang H. Dynamic structural remodeling of the human visual system prompted by bilateral retinal gene therapy. CURRENT RESEARCH IN NEUROBIOLOGY 2023; 4:100089. [PMID: 37397812 PMCID: PMC10313860 DOI: 10.1016/j.crneur.2023.100089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 02/03/2023] [Accepted: 05/01/2023] [Indexed: 07/04/2023] Open
Abstract
The impact of changes in visual input on neuronal circuitry is complex and much of our knowledge on human brain plasticity of the visual systems comes from animal studies. Reinstating vision in a group of patients with low vision through retinal gene therapy creates a unique opportunity to dynamically study the underlying process responsible for brain plasticity. Historically, increases in the axonal myelination of the visual pathway has been the biomarker for brain plasticity. Here, we demonstrate that to reach the long-term effects of myelination increase, the human brain may undergo demyelination as part of a plasticity process. The maximum change in dendritic arborization of the primary visual cortex and the neurite density along the geniculostriate tracks occurred at three months (3MO) post intervention, in line with timing for the peak changes in postnatal synaptogenesis within the visual cortex reported in animal studies. The maximum change at 3MO for both the gray and white matter significantly correlated with patients' clinical responses to light stimulations called full field sensitivity threshold (FST). Our results shed a new light on the underlying process of brain plasticity by challenging the concept of increase myelination being the hallmark of brain plasticity and instead reinforcing the idea of signal speed optimization as a dynamic process for brain plasticity.
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Affiliation(s)
- Manzar Ashtari
- Center for Advanced Retinal and Ocular Therapeutics (CAROT), University of Pennsylvania, Philadelphia, PA, 19104, United States
- Department of Ophthalmology, University of Pennsylvania, Philadelphia, PA, 19104, United States
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, 19104, United States
| | - Philip Cook
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, 19104, United States
| | - Mikhail Lipin
- Center for Advanced Retinal and Ocular Therapeutics (CAROT), University of Pennsylvania, Philadelphia, PA, 19104, United States
| | - Yinxi Yu
- Department of Ophthalmology, University of Pennsylvania, Philadelphia, PA, 19104, United States
| | - Gui-Shuang Ying
- Department of Ophthalmology, University of Pennsylvania, Philadelphia, PA, 19104, United States
| | - Albert Maguire
- Center for Advanced Retinal and Ocular Therapeutics (CAROT), University of Pennsylvania, Philadelphia, PA, 19104, United States
- Department of Ophthalmology, University of Pennsylvania, Philadelphia, PA, 19104, United States
| | - Jean Bennett
- Center for Advanced Retinal and Ocular Therapeutics (CAROT), University of Pennsylvania, Philadelphia, PA, 19104, United States
- Department of Ophthalmology, University of Pennsylvania, Philadelphia, PA, 19104, United States
| | - James Gee
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, 19104, United States
| | - Hui Zhang
- Centre for Medical Image Computing, University College London, London, United Kingdom
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Malakasis N, Chavlis S, Poirazi P. Synaptic turnover promotes efficient learning in bio-realistic spiking neural networks. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.22.541722. [PMID: 37292929 PMCID: PMC10245885 DOI: 10.1101/2023.05.22.541722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
While artificial machine learning systems achieve superhuman performance in specific tasks such as language processing, image and video recognition, they do so use extremely large datasets and huge amounts of power. On the other hand, the brain remains superior in several cognitively challenging tasks while operating with the energy of a small lightbulb. We use a biologically constrained spiking neural network model to explore how the neural tissue achieves such high efficiency and assess its learning capacity on discrimination tasks. We found that synaptic turnover, a form of structural plasticity, which is the ability of the brain to form and eliminate synapses continuously, increases both the speed and the performance of our network on all tasks tested. Moreover, it allows accurate learning using a smaller number of examples. Importantly, these improvements are most significant under conditions of resource scarcity, such as when the number of trainable parameters is halved and when the task difficulty is increased. Our findings provide new insights into the mechanisms that underlie efficient learning in the brain and can inspire the development of more efficient and flexible machine learning algorithms.
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Affiliation(s)
- Nikos Malakasis
- School of Medicine, University of Crete, Heraklion 70013, Greece
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion 70013, Greece
| | - Spyridon Chavlis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion 70013, Greece
| | - Panayiota Poirazi
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion 70013, Greece
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11
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Useinovic N, Near M, Cabrera OH, Boscolo A, Milosevic A, Harvey R, Newson A, Chastain-Potts S, Quillinan N, Jevtovic-Todorovic V. Neonatal sevoflurane exposure induces long-term changes in dendritic morphology in juvenile rats and mice. Exp Biol Med (Maywood) 2023; 248:641-655. [PMID: 37309741 PMCID: PMC10350807 DOI: 10.1177/15353702231170003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Accepted: 03/11/2023] [Indexed: 06/14/2023] Open
Abstract
General anesthetics are potent neurotoxins when given during early development, causing apoptotic deletion of substantial number of neurons and persistent neurocognitive and behavioral deficits in animals and humans. The period of intense synaptogenesis coincides with the peak of susceptibility to deleterious effects of anesthetics, a phenomenon particularly pronounced in vulnerable brain regions such as subiculum. With steadily accumulating evidence confirming that clinical doses and durations of anesthetics may permanently alter the physiological trajectory of brain development, we set out to investigate the long-term consequences on dendritic morphology of subicular pyramidal neurons and expression on genes regulating the complex neural processes such as neuronal connectivity, learning, and memory. Using a well-established model of anesthetic neurotoxicity in rats and mice neonatally exposed to sevoflurane, a volatile general anesthetic commonly used in pediatric anesthesia, we report that a single 6 h of continuous anesthesia administered at postnatal day (PND) 7 resulted in lasting dysregulation in subicular mRNA levels of cAMP responsive element modulator (Crem), cAMP responsive element-binding protein 1 (Creb1), and Protein phosphatase 3 catalytic subunit alpha, a subunit of calcineurin (Ppp3ca) (calcineurin) when examined during juvenile period at PND28. Given the critical role of these genes in synaptic development and neuronal plasticity, we deployed a set of histological measurements to investigate the implications of anesthesia-induced dysregulation of gene expression on morphology and complexity of surviving subicular pyramidal neurons. Our results indicate that neonatal exposure to sevoflurane induced lasting rearrangement of subicular dendrites, resulting in higher orders of complexity and increased branching with no significant effects on the soma of pyramidal neurons. Correspondingly, changes in dendritic complexity were paralleled by the increased spine density on apical dendrites, further highlighting the scope of anesthesia-induced dysregulation of synaptic development. We conclude that neonatal sevoflurane induced persistent genetic and morphological dysregulation in juvenile rodents, which could indicate heightened susceptibility toward cognitive and behavioral disorders we are beginning to recognize as sequelae of early-in-life anesthesia.
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Affiliation(s)
- Nemanja Useinovic
- Department of Anesthesiology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Michelle Near
- Department of Anesthesiology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Omar Hoseá Cabrera
- Department of Anesthesiology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Annalisa Boscolo
- Institute of Anesthesia and Intensive Care, Padua University Hospital, Padua 35128. Italy
- Department of Medicine (DIMED), University of Padua, Padua 35128, Italy
| | - Andjelko Milosevic
- Department of Anesthesiology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Rachel Harvey
- Oakland University William Beaumont School of Medicine, Rochester, MI 48309, USA
| | - Adre Newson
- Department of Anesthesiology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Shelby Chastain-Potts
- Department of Anesthesiology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Nidia Quillinan
- Department of Anesthesiology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- Neuronal Injury and Plasticity Program, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Vesna Jevtovic-Todorovic
- Department of Anesthesiology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
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12
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Ouyang L, Li Q, Rao S, Su R, Zhu Y, Du G, Xie J, Zhou F, Feng C, Fan G. Cognitive outcomes caused by low-level lead, cadmium, and mercury mixture exposure at distinct phases of brain development. Food Chem Toxicol 2023; 175:113707. [PMID: 36893892 DOI: 10.1016/j.fct.2023.113707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 02/16/2023] [Accepted: 03/02/2023] [Indexed: 03/09/2023]
Abstract
Contaminated water and food are the main sources of lead, cadmium, and mercury in the human body. Long-term and low-level ingestion of these toxic heavy metals may affect brain development and cognition. However, the neurotoxic effects of exposure to lead, cadmium, and mercury mixture (Pb + Cd + Hg) at different stages of brain development are rarely elucidated. In this study, different doses of low-level Pb + Cd + Hg were administered to Sprague-Dawley rats via drinking water during the critical stage of brain development, late stage, and after maturation, respectively. Our findings showed that Pb + Cd + Hg exposure decreased the density of memory- and learning-related dendritic spines in the hippocampus during the critical period of brain development, resulting in hippocampus-dependent spatial memory deficits. Only the density of learning-related dendritic spines was reduced during the late phase of brain development and a higher-dose of Pb + Cd + Hg exposure was required, which led to hippocampus-independent spatial memory abnormalities. Exposure to Pb + Cd + Hg after brain maturation revealed no significant change in dendritic spines or cognitive function. Further molecular analysis indicated that morphological and functional changes caused by Pb + Cd + Hg exposure during the critical phase were associated with PSD95 and GluA1 dysregulation. Collectively, the effects of Pb + Cd + Hg on cognition varied depending on the brain development stages.
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Affiliation(s)
- Lu Ouyang
- School of Public Health, Nanchang University, Nanchang, 330006, PR China; State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, PR China
| | - Qi Li
- School of Public Health, Nanchang University, Nanchang, 330006, PR China; State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, PR China
| | - Shaoqi Rao
- School of Public Health, Nanchang University, Nanchang, 330006, PR China
| | - Rui Su
- School of Public Health, Nanchang University, Nanchang, 330006, PR China
| | - Yanhui Zhu
- School of Public Health, Nanchang University, Nanchang, 330006, PR China
| | - Guihua Du
- School of Public Health, Nanchang University, Nanchang, 330006, PR China; Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang, 330006, PR China
| | - Jie Xie
- School of Public Health, Nanchang University, Nanchang, 330006, PR China; Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang, 330006, PR China
| | - Fankun Zhou
- School of Public Health, Nanchang University, Nanchang, 330006, PR China; Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang, 330006, PR China
| | - Chang Feng
- School of Public Health, Nanchang University, Nanchang, 330006, PR China; Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang, 330006, PR China
| | - Guangqin Fan
- School of Public Health, Nanchang University, Nanchang, 330006, PR China; State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, PR China; Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang, 330006, PR China.
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13
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Marquardt AE, VanRyzin JW, Fuquen RW, McCarthy MM. Social play experience in juvenile rats is indispensable for appropriate socio-sexual behavior in adulthood in males but not females. Front Behav Neurosci 2023; 16:1076765. [PMID: 36755666 PMCID: PMC9899815 DOI: 10.3389/fnbeh.2022.1076765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 12/07/2022] [Indexed: 01/24/2023] Open
Abstract
Social play is a dynamic and rewarding behavior abundantly expressed by most mammals during the juvenile period. While its exact function is debated, various rodent studies on the effects of juvenile social isolation suggest that participating in play is essential to appropriate behavior and reproductive success in adulthood. However, the vast majority of these studies were conducted in one sex only, a critical concern given the fact that there are known sex differences in play's expression: across nearly all species that play, males play more frequently and intensely than females, and there are qualitative sex differences in play patterns. Further limiting our understanding of the importance of play is the use of total isolation to prevent interactions with other juveniles. Here, we employed a novel cage design to specifically prevent play in rats while allowing for other forms of social interaction. We find that play deprivation during the juvenile period results in enduring sex-specific effects on later-life behavior, primarily in males. Males prevented from playing as juveniles exhibited decreased sexual behavior, hypersociability, and increased aggressiveness in adulthood, with no effects on these measures in females. Importantly, play deprivation had no effect on anxiety-like behavior, object memory, sex preference, or social recognition in either sex, showing the specificity of the identified impairments, though there were overall sex differences in many of these measures. Additionally, acute play deprivation impaired performance on a test of prosocial behavior in both sexes, indicating a difference in the motivation and/or ability to acquire this empathy-driven task. Together, these findings provide novel insight into the importance and function of juvenile social play and how this differs in males and females.
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Affiliation(s)
- Ashley E. Marquardt
- Program in Neuroscience, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Jonathan W. VanRyzin
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Rebeca W. Fuquen
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Margaret M. McCarthy
- Program in Neuroscience, University of Maryland School of Medicine, Baltimore, MD, United States,Department of Pharmacology, University of Maryland School of Medicine, Baltimore, MD, United States,*Correspondence: Margaret M. McCarthy
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14
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KASAI H. Unraveling the mysteries of dendritic spine dynamics: Five key principles shaping memory and cognition. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2023; 99:254-305. [PMID: 37821392 PMCID: PMC10749395 DOI: 10.2183/pjab.99.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2023] [Accepted: 07/11/2023] [Indexed: 10/13/2023]
Abstract
Recent research extends our understanding of brain processes beyond just action potentials and chemical transmissions within neural circuits, emphasizing the mechanical forces generated by excitatory synapses on dendritic spines to modulate presynaptic function. From in vivo and in vitro studies, we outline five central principles of synaptic mechanics in brain function: P1: Stability - Underpinning the integral relationship between the structure and function of the spine synapses. P2: Extrinsic dynamics - Highlighting synapse-selective structural plasticity which plays a crucial role in Hebbian associative learning, distinct from pathway-selective long-term potentiation (LTP) and depression (LTD). P3: Neuromodulation - Analyzing the role of G-protein-coupled receptors, particularly dopamine receptors, in time-sensitive modulation of associative learning frameworks such as Pavlovian classical conditioning and Thorndike's reinforcement learning (RL). P4: Instability - Addressing the intrinsic dynamics crucial to memory management during continual learning, spotlighting their role in "spine dysgenesis" associated with mental disorders. P5: Mechanics - Exploring how synaptic mechanics influence both sides of synapses to establish structural traces of short- and long-term memory, thereby aiding the integration of mental functions. We also delve into the historical background and foresee impending challenges.
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Affiliation(s)
- Haruo KASAI
- International Research Center for Neurointelligence (WPI-IRCN), UTIAS, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
- Laboratory of Structural Physiology, Center for Disease Biology and Integrative Medicine, Faculty of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
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15
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Heck N, Santos MD. Dendritic Spines in Learning and Memory: From First Discoveries to Current Insights. ADVANCES IN NEUROBIOLOGY 2023; 34:311-348. [PMID: 37962799 DOI: 10.1007/978-3-031-36159-3_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
The central nervous system is composed of neural ensembles, and their activity patterns are neural correlates of cognitive functions. Those ensembles are networks of neurons connected to each other by synapses. Most neurons integrate synaptic signal through a remarkable subcellular structure called spine. Dendritic spines are protrusions whose diverse shapes make them appear as a specific neuronal compartment, and they have been the focus of studies for more than a century. Soon after their first description by Ramón y Cajal, it has been hypothesized that spine morphological changes could modify neuronal connectivity and sustain cognitive abilities. Later studies demonstrated that changes in spine density and morphology occurred in experience-dependent plasticity during development, and in clinical cases of mental retardation. This gave ground for the assumption that dendritic spines are the particular locus of cerebral plasticity. With the discovery of synaptic long-term potentiation, a research program emerged with the aim to establish whether dendritic spine plasticity could explain learning and memory. The development of live imaging methods revealed on the one hand that dendritic spine remodeling is compatible with learning process and, on the other hand, that their long-term stability is compatible with lifelong memories. Furthermore, the study of the mechanisms of spine growth and maintenance shed new light on the rules of plasticity. In behavioral paradigms of memory, spine formation or elimination and morphological changes were found to correlate with learning. In a last critical step, recent experiments have provided evidence that dendritic spines play a causal role in learning and memory.
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Affiliation(s)
- Nicolas Heck
- Laboratory Neurosciences Paris Seine, Sorbonne Université, Paris, France.
| | - Marc Dos Santos
- Department of Neuroscience, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
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16
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Ciganok-Hückels N, Jehasse K, Kricsfalussy-Hrabár L, Ritter M, Rüland T, Kampa BM. Postnatal development of electrophysiological and morphological properties in layer 2/3 and layer 5 pyramidal neurons in the mouse primary visual cortex. Cereb Cortex 2022; 33:5875-5884. [PMID: 36453454 PMCID: PMC10183751 DOI: 10.1093/cercor/bhac467] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 11/04/2022] [Accepted: 11/05/2022] [Indexed: 12/03/2022] Open
Abstract
Abstract
Eye-opening is a critical point for laminar maturation of pyramidal neurons (PNs) in primary visual cortex. Knowing both the intrinsic properties and morphology of PNs from the visual cortex during development is crucial to contextualize the integration of visual inputs at different age stages. Few studies have reported changes in intrinsic excitability in these neurons but were restricted to only one layer or one stage of cortical development. Here, we used in vitro whole-cell patch-clamp to investigate the developmental impact on electrophysiological properties of layer 2/3 and layer 5 PNs in mouse visual cortex. Additionally, we evaluated the morphological changes before and after eye-opening and compared these in adult mice. Overall, we found a decrease in intrinsic excitability in both layers after eye-opening which remained stable between juvenile and adult mice. The basal dendritic length increased in layer 5 neurons, whereas spine density increased in layer 2/3 neurons after eye-opening. These data show increased number of synapses after onset of sensory input paralleled with a reduced excitability, presumably as homeostatic mechanism. Altogether, we provide a database of the properties of PNs in mouse visual cortex by considering the layer- and time-specific changes of these neurons during sensory development.
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Affiliation(s)
- Natalja Ciganok-Hückels
- Systems Neurophysiology, Institute of Zoology, RWTH Aachen University , 52074 Aachen , Germany
- Research Training Group 2416 MultiSenses-MultiScales, RWTH Aachen University , 52074 Aachen , Germany
| | - Kevin Jehasse
- Systems Neurophysiology, Institute of Zoology, RWTH Aachen University , 52074 Aachen , Germany
| | | | - Mira Ritter
- Systems Neurophysiology, Institute of Zoology, RWTH Aachen University , 52074 Aachen , Germany
| | - Thomas Rüland
- Systems Neurophysiology, Institute of Zoology, RWTH Aachen University , 52074 Aachen , Germany
- Research Training Group 2416 MultiSenses-MultiScales, RWTH Aachen University , 52074 Aachen , Germany
- Institute for Biological Information Processing (IBI-1), Forschungszentrum Jülich , 52428 Jülich , Germany
| | - Björn M Kampa
- Systems Neurophysiology, Institute of Zoology, RWTH Aachen University , 52074 Aachen , Germany
- Research Training Group 2416 MultiSenses-MultiScales, RWTH Aachen University , 52074 Aachen , Germany
- JARA BRAIN, Institute of Neuroscience and Medicine (INM-10), Forschungszentrum Jülich , 52428 Jülich , Germany
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17
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Stamps JA, Luttbeg B. Sensitive Period Diversity: Insights From Evolutionary Models. THE QUARTERLY REVIEW OF BIOLOGY 2022. [DOI: 10.1086/722637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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18
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Yayon N, Amsalem O, Zorbaz T, Yakov O, Dubnov S, Winek K, Dudai A, Adam G, Schmidtner AK, Tessier‐Lavigne M, Renier N, Habib N, Segev I, London M, Soreq H. High-throughput morphometric and transcriptomic profiling uncovers composition of naïve and sensory-deprived cortical cholinergic VIP/CHAT neurons. EMBO J 2022; 42:e110565. [PMID: 36377476 PMCID: PMC9811618 DOI: 10.15252/embj.2021110565] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 10/03/2022] [Accepted: 10/17/2022] [Indexed: 11/16/2022] Open
Abstract
Cortical neuronal networks control cognitive output, but their composition and modulation remain elusive. Here, we studied the morphological and transcriptional diversity of cortical cholinergic VIP/ChAT interneurons (VChIs), a sparse population with a largely unknown function. We focused on VChIs from the whole barrel cortex and developed a high-throughput automated reconstruction framework, termed PopRec, to characterize hundreds of VChIs from each mouse in an unbiased manner, while preserving 3D cortical coordinates in multiple cleared mouse brains, accumulating thousands of cells. We identified two fundamentally distinct morphological types of VChIs, bipolar and multipolar that differ in their cortical distribution and general morphological features. Following mild unilateral whisker deprivation on postnatal day seven, we found after three weeks both ipsi- and contralateral dendritic arborization differences and modified cortical depth and distribution patterns in the barrel fields alone. To seek the transcriptomic drivers, we developed NuNeX, a method for isolating nuclei from fixed tissues, to explore sorted VChIs. This highlighted differentially expressed neuronal structural transcripts, altered exitatory innervation pathways and established Elmo1 as a key regulator of morphology following deprivation.
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Affiliation(s)
- Nadav Yayon
- The Edmond and Lily Safra Center for Brain Sciences (ELSC), The Life Sciences InstituteThe Hebrew University of JerusalemJerusalemIsrael,The Department of Biological Chemistry, The Life Sciences InstituteThe Hebrew University of JerusalemJerusalemIsrael
| | - Oren Amsalem
- The Edmond and Lily Safra Center for Brain Sciences (ELSC), The Life Sciences InstituteThe Hebrew University of JerusalemJerusalemIsrael,The Department of Neurobiology, The Life Sciences InstituteThe Hebrew University of JerusalemJerusalemIsrael
| | - Tamara Zorbaz
- The Edmond and Lily Safra Center for Brain Sciences (ELSC), The Life Sciences InstituteThe Hebrew University of JerusalemJerusalemIsrael,The Department of Biological Chemistry, The Life Sciences InstituteThe Hebrew University of JerusalemJerusalemIsrael,Biochemistry and Organic Analytical Chemistry UnitThe Institute of Medical Research and Occupational HealthZagrebCroatia
| | - Or Yakov
- The Department of Biological Chemistry, The Life Sciences InstituteThe Hebrew University of JerusalemJerusalemIsrael
| | - Serafima Dubnov
- The Edmond and Lily Safra Center for Brain Sciences (ELSC), The Life Sciences InstituteThe Hebrew University of JerusalemJerusalemIsrael,The Department of Biological Chemistry, The Life Sciences InstituteThe Hebrew University of JerusalemJerusalemIsrael
| | - Katarzyna Winek
- The Edmond and Lily Safra Center for Brain Sciences (ELSC), The Life Sciences InstituteThe Hebrew University of JerusalemJerusalemIsrael,The Department of Biological Chemistry, The Life Sciences InstituteThe Hebrew University of JerusalemJerusalemIsrael
| | - Amir Dudai
- The Edmond and Lily Safra Center for Brain Sciences (ELSC), The Life Sciences InstituteThe Hebrew University of JerusalemJerusalemIsrael,The Department of Neurobiology, The Life Sciences InstituteThe Hebrew University of JerusalemJerusalemIsrael
| | - Gil Adam
- The Department of Biological Chemistry, The Life Sciences InstituteThe Hebrew University of JerusalemJerusalemIsrael
| | - Anna K Schmidtner
- The Edmond and Lily Safra Center for Brain Sciences (ELSC), The Life Sciences InstituteThe Hebrew University of JerusalemJerusalemIsrael
| | | | - Nicolas Renier
- Sorbonne Université, Paris Brain Institute ‐ ICM, INSERM, CNRS, AP‐HP, Hôpital de la Pitié SalpêtrièreParisFrance
| | - Naomi Habib
- The Edmond and Lily Safra Center for Brain Sciences (ELSC), The Life Sciences InstituteThe Hebrew University of JerusalemJerusalemIsrael,The Department of Neurobiology, The Life Sciences InstituteThe Hebrew University of JerusalemJerusalemIsrael
| | - Idan Segev
- The Edmond and Lily Safra Center for Brain Sciences (ELSC), The Life Sciences InstituteThe Hebrew University of JerusalemJerusalemIsrael,The Department of Neurobiology, The Life Sciences InstituteThe Hebrew University of JerusalemJerusalemIsrael
| | - Michael London
- The Edmond and Lily Safra Center for Brain Sciences (ELSC), The Life Sciences InstituteThe Hebrew University of JerusalemJerusalemIsrael,The Department of Neurobiology, The Life Sciences InstituteThe Hebrew University of JerusalemJerusalemIsrael
| | - Hermona Soreq
- The Edmond and Lily Safra Center for Brain Sciences (ELSC), The Life Sciences InstituteThe Hebrew University of JerusalemJerusalemIsrael,The Department of Biological Chemistry, The Life Sciences InstituteThe Hebrew University of JerusalemJerusalemIsrael
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19
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Curia G, Estrada-Camarena E, Manjarrez E, Mizuno H. Editorial: In vivo investigations on neurological disorders: From traditional approaches to forefront technologies. Front Neurosci 2022; 16:1052089. [PMID: 36330344 PMCID: PMC9623258 DOI: 10.3389/fnins.2022.1052089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Accepted: 10/05/2022] [Indexed: 11/25/2022] Open
Affiliation(s)
- Giulia Curia
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
- *Correspondence: Giulia Curia
| | - Erika Estrada-Camarena
- Laboratory of Neuropsychopharmacology, Neuroscience, National Institute of Psychiatry Ramon de la Fuente Muñiz (INPRFM), Mexico City, Mexico
| | - Elias Manjarrez
- Institute of Physiology, Benemerita Universidad Autonoma de Puebla, Puebla, Mexico
| | - Hidenobu Mizuno
- International Research Center for Medical Sciences (IRCMS), Kumamoto University, Kumamoto, Japan
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20
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Frias ES, Hoseini MS, Krukowski K, Paladini MS, Grue K, Ureta G, Rienecker KDA, Walter P, Stryker MP, Rosi S. Aberrant cortical spine dynamics after concussive injury are reversed by integrated stress response inhibition. Proc Natl Acad Sci U S A 2022; 119:e2209427119. [PMID: 36227915 PMCID: PMC9586300 DOI: 10.1073/pnas.2209427119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 09/09/2022] [Indexed: 11/18/2022] Open
Abstract
Traumatic brain injury (TBI) is a leading cause of long-term neurological disability in the world and the strongest environmental risk factor for the development of dementia. Even mild TBI (resulting from concussive injuries) is associated with a greater than twofold increase in the risk of dementia onset. Little is known about the cellular mechanisms responsible for the progression of long-lasting cognitive deficits. The integrated stress response (ISR), a phylogenetically conserved pathway involved in the cellular response to stress, is activated after TBI, and inhibition of the ISR-even weeks after injury-can reverse behavioral and cognitive deficits. However, the cellular mechanisms by which ISR inhibition restores cognition are unknown. Here, we used longitudinal two-photon imaging in vivo after concussive injury in mice to study dendritic spine dynamics in the parietal cortex, a brain region involved in working memory. Concussive injury profoundly altered spine dynamics measured up to a month after injury. Strikingly, brief pharmacological treatment with the drug-like small-molecule ISR inhibitor ISRIB entirely reversed structural changes measured in the parietal cortex and the associated working memory deficits. Thus, both neural and cognitive consequences of concussive injury are mediated in part by activation of the ISR and can be corrected by its inhibition. These findings suggest that targeting ISR activation could serve as a promising approach to the clinical treatment of chronic cognitive deficits after TBI.
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Affiliation(s)
- Elma S. Frias
- Department of Physical Therapy and Rehabilitation, University of California, San Francisco, CA 94143
- Brain and Spinal Injury Center, University of California, San Francisco, CA 94143
| | - Mahmood S. Hoseini
- Department of Physiology, University of California, San Francisco, CA 94143
| | - Karen Krukowski
- Department of Physical Therapy and Rehabilitation, University of California, San Francisco, CA 94143
- Brain and Spinal Injury Center, University of California, San Francisco, CA 94143
| | - Maria Serena Paladini
- Department of Physical Therapy and Rehabilitation, University of California, San Francisco, CA 94143
- Brain and Spinal Injury Center, University of California, San Francisco, CA 94143
| | - Katherine Grue
- Department of Physical Therapy and Rehabilitation, University of California, San Francisco, CA 94143
- Brain and Spinal Injury Center, University of California, San Francisco, CA 94143
| | - Gonzalo Ureta
- Department of Translational Research, Protein Folding and Disease Laboratory, Fundación Ciencia & Vida, Santiago, 7750000, Chile
| | - Kira D. A. Rienecker
- Department of Physical Therapy and Rehabilitation, University of California, San Francisco, CA 94143
- Brain and Spinal Injury Center, University of California, San Francisco, CA 94143
| | - Peter Walter
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA 94143
- HHMI, University of California, San Francisco, CA 94143
| | - Michael P. Stryker
- Department of Physiology, University of California, San Francisco, CA 94143
- Kavli Institute of Fundamental Neuroscience, University of California, San Francisco, CA 94143
| | - Susanna Rosi
- Department of Physical Therapy and Rehabilitation, University of California, San Francisco, CA 94143
- Brain and Spinal Injury Center, University of California, San Francisco, CA 94143
- Kavli Institute of Fundamental Neuroscience, University of California, San Francisco, CA 94143
- Department of Neurological Surgery, University of California, San Francisco, CA 94143
- Weill Institute for Neuroscience, University of California, San Francisco, CA 94143
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21
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Mikheeva I, Mikhailova G, Zhujkova N, Shtanchaev R, Arkhipov V, Pavlik L. Studying the structure of the nucleus of the trochlear nerve in mice through 7 days of readaptation to earth gravity after spaceflight. Brain Res 2022; 1795:148077. [PMID: 36096199 DOI: 10.1016/j.brainres.2022.148077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 09/01/2022] [Accepted: 09/04/2022] [Indexed: 11/30/2022]
Abstract
The negative effect of hypogravity on the human organism is manifested to a greater extent after the astronauts return to the conditions of habitual gravity. In this work, to elucidate the causes underlying atypical nystagmus, arising after the flight, we studied structural changes in the motoneurons of the trochlear nerve after a 7-day readaptation of mice to the conditions of Earth's gravity. It is known, that motoneurons of the trochlear nerve innervate the muscle that controls the movement of the eyes in the vertical direction. We showed that the number of axodendritic synapses and some other morphological parameters of motoneurons changed by microgravity can return to their original state in 7 days. However, according to some parameters, motoneurons retain a "memory" of the action of microgravity and do not completely restore the structure. The volume of the soma, the shape of the nuclei, the number and orientation of dendrites do not return to pre-flight parameters. The number of dendrites after 7 days of adaptation remained increased, and the proportion of dendrites in the ventrolateral direction became 2.5 times greater than in motoneurons after space flight. The increased number of mitochondria after space flight became even more significant after readaptation. Microgravity-induced plastic changes retain to some extent "memory traces" after readaptation to Earth's gravity. It can be assumed that the restoration of the function of the trochlear nuclei (overcoming nystagmus) is carried out not only by reversible restoration of the structure of neurons, but partially using those mechanisms that are formed in weightlessness.
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Affiliation(s)
- Irina Mikheeva
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow Region 142290 Russia.
| | - Gulnara Mikhailova
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow Region 142290 Russia
| | - Natalya Zhujkova
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow Region 142290 Russia
| | - Rashid Shtanchaev
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow Region 142290 Russia
| | - Vladimir Arkhipov
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow Region 142290 Russia
| | - Lyubov Pavlik
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow Region 142290 Russia
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22
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Terstege DJ, Durante IM, Epp JR. Brain-wide neuronal activation and functional connectivity are modulated by prior exposure to repetitive learning episodes. Front Behav Neurosci 2022; 16:907707. [PMID: 36160680 PMCID: PMC9501867 DOI: 10.3389/fnbeh.2022.907707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 08/23/2022] [Indexed: 11/26/2022] Open
Abstract
Memory storage and retrieval are shaped by past experiences. Prior learning and memory episodes have numerous impacts on brain structure from micro to macroscale. Previous experience with specific forms of learning increases the efficiency of future learning. It is less clear whether such practice effects on one type of memory might also have transferable effects to other forms of memory. Different forms of learning and memory rely on different brain-wide networks but there are many points of overlap in these networks. Enhanced structural or functional connectivity caused by one type of learning may be transferable to another type of learning due to overlap in underlying memory networks. Here, we investigated the impact of prior chronic spatial training on the task-specific functional connectivity related to subsequent contextual fear memory recall in mice. Our results show that mice exposed to prior spatial training exhibited decreased brain-wide activation compared to control mice during the retrieval of a context fear memory. With respect to functional connectivity, we observed changes in several network measures, notably an increase in global efficiency. Interestingly, we also observed an increase in network resilience based on simulated targeted node deletion. Overall, this study suggests that chronic learning has transferable effects on the functional connectivity networks of other types of learning and memory. The generalized enhancements in network efficiency and resilience suggest that learning itself may protect brain networks against deterioration.
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23
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Changes in Dendritic Spine Morphology and Density of Granule Cells in the Olfactory Bulb of Anguilla anguilla (L., 1758): A Possible Way to Understand Orientation and Migratory Behavior. BIOLOGY 2022; 11:biology11081244. [PMID: 36009870 PMCID: PMC9405168 DOI: 10.3390/biology11081244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 08/18/2022] [Accepted: 08/18/2022] [Indexed: 11/18/2022]
Abstract
Simple Summary The olfactory bulb can process odour cues through granular cells (GCs) and dendritic spines, changing their synaptic plasticity properties and their morphology. The GCs’ dendritic spines density and morphology were analysed in Anguilla anguilla, considering the olfaction as a driver involved in fish orientation and migration. For the head and neck morphology, spines were classified as mushroom, long thin, stubby, and filopodia. Spines’ density decreased from juvenile migrants to no-migrant stages and increased in the adult migrants. Spines’ density was comparable between glass and silver eels as an adaptation to migration, while at non-migrating phases, spines’ density decreased. For its phylogenetic Elopomorph attribution and its complex life cycle, A. anguilla could be recommended as a model species to study the development of dendritic spines in GCs of the olfactory bulb. Considering the role of olfaction in the orientation and migration of A. anguilla, the modification of environmental stimuli (ocean alterations and climate change) could represent contributing factors that threaten this critically endangered species. Abstract Olfaction could represent a pivotal process involved in fish orientation and migration. The olfactory bulb can manage olfactive signals at the granular cell (GC) and dendritic spine levels for their synaptic plasticity properties and changing their morphology and structural stability after environmental odour cues. The GCs’ dendritic spine density and morphology were analysed across the life stages of the catadromous Anguilla anguilla. According to the head and neck morphology, spines were classified as mushroom (M), long thin (LT), stubby (S), and filopodia (F). Total spines’ density decreased from juvenile migrants to no-migrant stages, to increase again in the adult migrant stage. Mean spines’ density was comparable between glass and silver eels as an adaptation to migration. At non-migrating phases, spines’ density decreased for M and LT, while M, LT, and S density increased in silver eels. A great dendritic spine development was found in the two migratory phases, regressing in trophic phases, but that could be recreated in adults, tracing the migratory memory of the routes travelled in juvenile phases. For its phylogenetic Elopomorph attribution and its complex life cycle, A. anguilla could be recommended as a model species to study the development of dendritic spines in GCs of the olfactory bulb as an index of synaptic plasticity involved in the modulation of olfactory stimuli. If olfaction is involved in the orientation and migration of A. anguilla and if eels possess a memory, these processes could be influenced by the modification of environmental stimuli (ocean alterations and rapid climate change) contributing to threatening this critically endangered species.
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Lee S, Kume H, Urakubo H, Kasai H, Ishii S. Tri-view two-photon microscopic image registration and deblurring with convolutional neural networks. Neural Netw 2022; 152:57-69. [DOI: 10.1016/j.neunet.2022.04.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 02/10/2022] [Accepted: 04/11/2022] [Indexed: 10/18/2022]
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25
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Juvenile depletion of microglia reduces orientation but not high spatial frequency selectivity in mouse V1. Sci Rep 2022; 12:12779. [PMID: 35896554 PMCID: PMC9329297 DOI: 10.1038/s41598-022-15503-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 06/24/2022] [Indexed: 01/26/2023] Open
Abstract
Microglia contain multiple mechanisms that shape the synaptic landscape during postnatal development. Whether the synaptic changes mediated by microglia reflect the developmental refinement of neuronal responses in sensory cortices, however, remains poorly understood. In postnatal life, the development of increased orientation and spatial frequency selectivity of neuronal responses in primary visual cortex (V1) supports the emergence of high visual acuity. Here, we used the colony-stimulating factor 1 receptor (CSF1R) inhibitor PLX5622 to rapidly and durably deplete microglia in mice during the juvenile period in which increased orientation and spatial frequency selectivity emerge. Excitatory and inhibitory tuning properties were measured simultaneously using multi-photon calcium imaging in layer II/III of mouse V1. We found that microglia depletion generally increased evoked activity which, in turn, reduced orientation selectivity. Surprisingly, microglia were not required for the emergence of high spatial frequency tuned responses. In addition, microglia depletion did not perturb cortical binocularity, suggesting normal depth processing. Together, our finding that orientation and high spatial frequency selectivity in V1 are differentially supported by microglia reveal that microglia are required normal sensory processing, albeit selectively.
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Redman WT, Wolcott NS, Montelisciani L, Luna G, Marks TD, Sit KK, Yu CH, Smith S, Goard MJ. Long-term transverse imaging of the hippocampus with glass microperiscopes. eLife 2022; 11:75391. [PMID: 35775393 PMCID: PMC9249394 DOI: 10.7554/elife.75391] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 06/12/2022] [Indexed: 11/19/2022] Open
Abstract
The hippocampus consists of a stereotyped neuronal circuit repeated along the septal-temporal axis. This transverse circuit contains distinct subfields with stereotyped connectivity that support crucial cognitive processes, including episodic and spatial memory. However, comprehensive measurements across the transverse hippocampal circuit in vivo are intractable with existing techniques. Here, we developed an approach for two-photon imaging of the transverse hippocampal plane in awake mice via implanted glass microperiscopes, allowing optical access to the major hippocampal subfields and to the dendritic arbor of pyramidal neurons. Using this approach, we tracked dendritic morphological dynamics on CA1 apical dendrites and characterized spine turnover. We then used calcium imaging to quantify the prevalence of place and speed cells across subfields. Finally, we measured the anatomical distribution of spatial information, finding a non-uniform distribution of spatial selectivity along the DG-to-CA1 axis. This approach extends the existing toolbox for structural and functional measurements of hippocampal circuitry.
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Affiliation(s)
- William T Redman
- Interdepartmental Graduate Program in Dynamical Neuroscience, University of California, Santa Barbara, United States
| | - Nora S Wolcott
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, United States
| | - Luca Montelisciani
- Cognitive and Systems Neuroscience Group, University of Amsterdam, Amsterdam, Netherlands
| | - Gabriel Luna
- Neuroscience Research Institute, University of California, Santa Barbara, United States
| | - Tyler D Marks
- Neuroscience Research Institute, University of California, Santa Barbara, United States
| | - Kevin K Sit
- Department of Psychological and Brain Sciences, University of California, Santa Barbara, United States
| | - Che-Hang Yu
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, United States
| | - Spencer Smith
- Neuroscience Research Institute, University of California, Santa Barbara, United States.,Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, United States
| | - Michael J Goard
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, United States.,Neuroscience Research Institute, University of California, Santa Barbara, United States.,Department of Psychological and Brain Sciences, University of California, Santa Barbara, United States
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27
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Learning binds new inputs into functional synaptic clusters via spinogenesis. Nat Neurosci 2022; 25:726-737. [PMID: 35654957 DOI: 10.1038/s41593-022-01086-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 04/26/2022] [Indexed: 11/08/2022]
Abstract
Learning induces the formation of new excitatory synapses in the form of dendritic spines, but their functional properties remain unknown. Here, using longitudinal in vivo two-photon imaging and correlated electron microscopy of dendritic spines in the motor cortex of mice during motor learning, we describe a framework for the formation, survival and resulting function of new, learning-related spines. Specifically, our data indicate that the formation of new spines during learning is guided by the potentiation of functionally clustered preexisting spines exhibiting task-related activity during earlier sessions of learning. We present evidence that this clustered potentiation induces the local outgrowth of multiple filopodia from the nearby dendrite, locally sampling the adjacent neuropil for potential axonal partners, likely via targeting preexisting presynaptic boutons. Successful connections are then selected for survival based on co-activity with nearby task-related spines, ensuring that the new spine preserves functional clustering. The resulting locally coherent activity of new spines signals the learned movement. Furthermore, we found that a majority of new spines synapse with axons previously unrepresented in these dendritic domains. Thus, learning involves the binding of new information streams into functional synaptic clusters to subserve learned behaviors.
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Kucharz K, Kutuzov N, Zhukov O, Mathiesen Janiurek M, Lauritzen M. Shedding Light on the Blood-Brain Barrier Transport with Two-Photon Microscopy In Vivo. Pharm Res 2022; 39:1457-1468. [PMID: 35578062 DOI: 10.1007/s11095-022-03266-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 04/19/2022] [Indexed: 02/06/2023]
Abstract
Treatment of brain disorders relies on efficient delivery of therapeutics to the brain, which is hindered by the blood-brain barrier (BBB). The work of Prof. Margareta Hammarlund-Udenaes was instrumental in understanding the principles of drug delivery to the brain and developing new tools to study it. Here, we show how some of the concepts developed in her research can be translated to in vivo 2-photon microscopy (2PM) studies of the BBB. We primarily focus on the methods developed in our laboratory to characterize the paracellular diffusion, adsorptive-mediated transcytosis, and receptor-mediated transcytosis of drug nanocarriers at the microscale, illustrating how 2PM can deepen our understanding of the mechanisms of drug delivery to the brain.
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Affiliation(s)
- Krzysztof Kucharz
- Department of Neuroscience, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Nikolay Kutuzov
- Department of Neuroscience, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Oleg Zhukov
- Department of Neuroscience, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Mette Mathiesen Janiurek
- Department of Neuroscience, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Martin Lauritzen
- Department of Neuroscience, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark. .,Department of Clinical Neurophysiology, Rigshospitalet, Glostrup, Denmark.
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Lawal O, Ulloa Severino FP, Eroglu C. The role of astrocyte structural plasticity in regulating neural circuit function and behavior. Glia 2022; 70:1467-1483. [PMID: 35535566 PMCID: PMC9233050 DOI: 10.1002/glia.24191] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Revised: 04/28/2022] [Accepted: 04/28/2022] [Indexed: 12/12/2022]
Abstract
Brain circuits undergo substantial structural changes during development, driven by the formation, stabilization, and elimination of synapses. Synaptic connections continue to undergo experience‐dependent structural rearrangements throughout life, which are postulated to underlie learning and memory. Astrocytes, a major glial cell type in the brain, are physically in contact with synaptic circuits through their structural ensheathment of synapses. Astrocytes strongly contribute to the remodeling of synaptic structures in healthy and diseased central nervous systems by regulating synaptic connectivity and behaviors. However, whether structural plasticity of astrocytes is involved in their critical functions at the synapse is unknown. This review will discuss the emerging evidence linking astrocytic structural plasticity to synaptic circuit remodeling and regulation of behaviors. Moreover, we will survey possible molecular and cellular mechanisms regulating the structural plasticity of astrocytes and their non‐cell‐autonomous effects on neuronal plasticity. Finally, we will discuss how astrocyte morphological changes in different physiological states and disease conditions contribute to neuronal circuit function and dysfunction.
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Affiliation(s)
- Oluwadamilola Lawal
- Department of Cell Biology, Duke University Medical Center, Durham, North Carolina, USA.,Department of Neurobiology, Duke University Medical Center, Durham, North Carolina, USA
| | - Francesco Paolo Ulloa Severino
- Department of Cell Biology, Duke University Medical Center, Durham, North Carolina, USA.,Department of Neuroscience and Psychology, Duke University, Durham, North Carolina, USA.,Howard Hughes Medical Institute, Duke University, Durham, North Carolina, USA
| | - Cagla Eroglu
- Department of Cell Biology, Duke University Medical Center, Durham, North Carolina, USA.,Department of Neurobiology, Duke University Medical Center, Durham, North Carolina, USA.,Howard Hughes Medical Institute, Duke University, Durham, North Carolina, USA.,Duke Institute for Brain Sciences, Durham, North Carolina, USA
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30
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Chen CC, Brumberg JC. Sensory Experience as a Regulator of Structural Plasticity in the Developing Whisker-to-Barrel System. Front Cell Neurosci 2022; 15:770453. [PMID: 35002626 PMCID: PMC8739903 DOI: 10.3389/fncel.2021.770453] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 11/22/2021] [Indexed: 12/28/2022] Open
Abstract
Cellular structures provide the physical foundation for the functionality of the nervous system, and their developmental trajectory can be influenced by the characteristics of the external environment that an organism interacts with. Historical and recent works have determined that sensory experiences, particularly during developmental critical periods, are crucial for information processing in the brain, which in turn profoundly influence neuronal and non-neuronal cortical structures that subsequently impact the animals' behavioral and cognitive outputs. In this review, we focus on how altering sensory experience influences normal/healthy development of the central nervous system, particularly focusing on the cerebral cortex using the rodent whisker-to-barrel system as an illustrative model. A better understanding of structural plasticity, encompassing multiple aspects such as neuronal, glial, and extra-cellular domains, provides a more integrative view allowing for a deeper appreciation of how all aspects of the brain work together as a whole.
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Affiliation(s)
- Chia-Chien Chen
- Department of Psychology, Queens College City University of New York, Flushing, NY, United States.,Department of Neuroscience, Duke Kunshan University, Suzhou, China
| | - Joshua C Brumberg
- Department of Psychology, Queens College City University of New York, Flushing, NY, United States.,The Biology (Neuroscience) and Psychology (Behavioral and Cognitive Neuroscience) PhD Programs, The Graduate Center, The City University of New York, New York, NY, United States
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31
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Knipper M, Singer W, Schwabe K, Hagberg GE, Li Hegner Y, Rüttiger L, Braun C, Land R. Disturbed Balance of Inhibitory Signaling Links Hearing Loss and Cognition. Front Neural Circuits 2022; 15:785603. [PMID: 35069123 PMCID: PMC8770933 DOI: 10.3389/fncir.2021.785603] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 12/08/2021] [Indexed: 12/19/2022] Open
Abstract
Neuronal hyperexcitability in the central auditory pathway linked to reduced inhibitory activity is associated with numerous forms of hearing loss, including noise damage, age-dependent hearing loss, and deafness, as well as tinnitus or auditory processing deficits in autism spectrum disorder (ASD). In most cases, the reduced central inhibitory activity and the accompanying hyperexcitability are interpreted as an active compensatory response to the absence of synaptic activity, linked to increased central neural gain control (increased output activity relative to reduced input). We here suggest that hyperexcitability also could be related to an immaturity or impairment of tonic inhibitory strength that typically develops in an activity-dependent process in the ascending auditory pathway with auditory experience. In these cases, high-SR auditory nerve fibers, which are critical for the shortest latencies and lowest sound thresholds, may have either not matured (possibly in congenital deafness or autism) or are dysfunctional (possibly after sudden, stressful auditory trauma or age-dependent hearing loss linked with cognitive decline). Fast auditory processing deficits can occur despite maintained basal hearing. In that case, tonic inhibitory strength is reduced in ascending auditory nuclei, and fast inhibitory parvalbumin positive interneuron (PV-IN) dendrites are diminished in auditory and frontal brain regions. This leads to deficits in central neural gain control linked to hippocampal LTP/LTD deficiencies, cognitive deficits, and unbalanced extra-hypothalamic stress control. Under these conditions, a diminished inhibitory strength may weaken local neuronal coupling to homeostatic vascular responses required for the metabolic support of auditory adjustment processes. We emphasize the need to distinguish these two states of excitatory/inhibitory imbalance in hearing disorders: (i) Under conditions of preserved fast auditory processing and sustained tonic inhibitory strength, an excitatory/inhibitory imbalance following auditory deprivation can maintain precise hearing through a memory linked, transient disinhibition that leads to enhanced spiking fidelity (central neural gain⇑) (ii) Under conditions of critically diminished fast auditory processing and reduced tonic inhibitory strength, hyperexcitability can be part of an increased synchronization over a broader frequency range, linked to reduced spiking reliability (central neural gain⇓). This latter stage mutually reinforces diminished metabolic support for auditory adjustment processes, increasing the risks for canonical dementia syndromes.
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Affiliation(s)
- Marlies Knipper
- Department of Otolaryngology, Head and Neck Surgery, Tübingen Hearing Research Center (THRC), Molecular Physiology of Hearing, University of Tübingen, Tübingen, Germany
- *Correspondence: Marlies Knipper,
| | - Wibke Singer
- Department of Otolaryngology, Head and Neck Surgery, Tübingen Hearing Research Center (THRC), Molecular Physiology of Hearing, University of Tübingen, Tübingen, Germany
| | - Kerstin Schwabe
- Experimental Neurosurgery, Department of Neurosurgery, Hannover Medical School, Hanover, Germany
| | - Gisela E. Hagberg
- Department of Biomedical Magnetic Resonance, University Hospital Tübingen (UKT), Tübingen, Germany
- High-Field Magnetic Resonance, Max Planck Institute for Biological Cybernetics, Tübingen, Germany
| | - Yiwen Li Hegner
- MEG Center, University of Tübingen, Tübingen, Germany
- Center of Neurology, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Lukas Rüttiger
- Department of Otolaryngology, Head and Neck Surgery, Tübingen Hearing Research Center (THRC), Molecular Physiology of Hearing, University of Tübingen, Tübingen, Germany
| | - Christoph Braun
- MEG Center, University of Tübingen, Tübingen, Germany
- Center of Neurology, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Rüdiger Land
- Department of Experimental Otology, Institute for Audioneurotechnology, Hannover Medical School, Hanover, Germany
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32
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Lee J, Urban-Ciecko J, Park E, Zhu M, Myal SE, Margolis DJ, Barth AL. FosGFP expression does not capture a sensory learning-related engram in superficial layers of mouse barrel cortex. Proc Natl Acad Sci U S A 2021; 118:e2112212118. [PMID: 34930843 PMCID: PMC8719899 DOI: 10.1073/pnas.2112212118] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/07/2021] [Indexed: 11/18/2022] Open
Abstract
Immediate-early gene (IEG) expression has been used to identify small neural ensembles linked to a particular experience, based on the principle that a selective subset of activated neurons will encode specific memories or behavioral responses. The majority of these studies have focused on "engrams" in higher-order brain areas where more abstract or convergent sensory information is represented, such as the hippocampus, prefrontal cortex, or amygdala. In primary sensory cortex, IEG expression can label neurons that are responsive to specific sensory stimuli, but experience-dependent shaping of neural ensembles marked by IEG expression has not been demonstrated. Here, we use a fosGFP transgenic mouse to longitudinally monitor in vivo expression of the activity-dependent gene c-fos in superficial layers (L2/3) of primary somatosensory cortex (S1) during a whisker-dependent learning task. We find that sensory association training does not detectably alter fosGFP expression in L2/3 neurons. Although training broadly enhances thalamocortical synaptic strength in pyramidal neurons, we find that synapses onto fosGFP+ neurons are not selectively increased by training; rather, synaptic strengthening is concentrated in fosGFP- neurons. Taken together, these data indicate that expression of the IEG reporter fosGFP does not facilitate identification of a learning-specific engram in L2/3 in barrel cortex during whisker-dependent sensory association learning.
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Affiliation(s)
- Jiseok Lee
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213
| | - Joanna Urban-Ciecko
- Nencki Institute of Experimental Biology of the Polish Academy of Sciences, 02-093 Warsaw, Poland
| | - Eunsol Park
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213
| | - Mo Zhu
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213
| | - Stephanie E Myal
- University of Pittsburgh School of Medicine, Pittsburgh, PA 15213
| | - David J Margolis
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, Piscataway, NJ 08854
| | - Alison L Barth
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213;
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33
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Sheikh A, Meng X, Kao JPY, Kanold PO. Neonatal Hypoxia-Ischemia Causes Persistent Intracortical Circuit Changes in Layer 4 of Rat Auditory Cortex. Cereb Cortex 2021; 32:2575-2589. [PMID: 34729599 DOI: 10.1093/cercor/bhab365] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 09/01/2021] [Accepted: 09/02/2021] [Indexed: 11/12/2022] Open
Abstract
The connection between early brain injury and subsequent development of disorders is unknown. Neonatal hypoxia-ischemia (HI) alters circuits associated with subplate neurons (SPNs). SPNs are among the first maturing cortical neurons, project to thalamorecipient layer 4 (L4), and are required for the development of thalamocortical connections. Thus, early HI might influence L4 and such influence might persist. We investigated functional circuits to L4 neurons in neonatal rat HI models of different severities (mild and moderate) shortly after injury and at adolescence. We used laser-scanning photostimulation in slices of auditory cortex during P5-10 and P18-23. Mild injuries did not initially (P6/P7) alter the convergence of excitatory inputs from L2/3, but hyperconnectivity emerged by P8-10. Inputs from L4 showed initial hypoconnectivity which resolved by P8-10. Moderate injuries resulted in initial hypoconnectivity from both layers which resolved by P8-10 and led to persistent strengthening of connections. Inhibitory inputs to L4 cells showed similar changes. Functional changes were mirrored by reduced dendritic complexity. We also observed a persistent increase in similarity of L4 circuits, suggesting that HI interferes with developmental circuit refinement and diversification. Altogether, our results show that neonatal HI injuries lead to persistent changes in intracortical connections.
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Affiliation(s)
- Aminah Sheikh
- Department of Biology, University of Maryland, College Park, MD 20742, USA.,Neuroscience and Cognitive Science Program, University of Maryland, College Park, MD 20742, USA
| | - Xiangying Meng
- Department of Biology, University of Maryland, College Park, MD 20742, USA.,Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Joseph P Y Kao
- Center for Biomedical Engineering and Technology, and Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Patrick O Kanold
- Department of Biology, University of Maryland, College Park, MD 20742, USA.,Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21205, USA
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34
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Wong EL, Strohm A, Atlas J, Lamantia C, Majewska AK. Dynamics of microglia and dendritic spines in early adolescent cortex after developmental alcohol exposure. Dev Neurobiol 2021; 81:786-804. [PMID: 34228891 DOI: 10.1002/dneu.22843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Revised: 05/26/2021] [Accepted: 06/13/2021] [Indexed: 11/05/2022]
Abstract
Fetal alcohol spectrum disorder patients suffer from many cognitive disabilities. These include impaired auditory, visual, and tactile sensory information processing, making it more difficult for these patients to learn to navigate social scenarios. Rodent studies have shown that alcohol exposure during the brain growth spurt (BGS) can lead to acute neuronal apoptosis and an immunological response by microglia in the somatosensory cortex. Since microglia have critical physiological functions, including the support of excitatory synapse remodeling via interactions with dendritic spines, we sought to understand whether BGS alcohol exposure has long-term effects on microglial or dendritic spine dynamics. Using in vivo two-photon microscopy in 4-5 week old mice, we evaluated microglial functions such as process motility, the response to tissue injury, and the dynamics of physical interactions between microglial processes and dendritic spines. We also investigated potential differences in the morphology, density, or dynamics of dendritic spines in layer I/II primary sensory cortex of control and BGS alcohol exposed mice. We found that microglial process motility and contact with dendritic spines were not altered after BGS alcohol exposure. While the response of microglial processes toward tissue injury was not significantly altered by prior alcohol exposure, there was a trend suggesting that alcohol early in life may prime microglia to respond more quickly to secondary injury. Spine density, morphology, stability, and remodeling over time were not perturbed after BGS alcohol exposure. We demonstrate that after BGS alcohol exposure, the physiological functions of microglia and excitatory neurons remain intact in early adolescence.
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Affiliation(s)
- Elissa L Wong
- Department of Neuroscience, University of Rochester Medical Center, Rochester, New York, US.,Department of Environmental Medicine, University of Rochester Medical Center, New York, US
| | - Alexandra Strohm
- Department of Environmental Medicine, University of Rochester Medical Center, New York, US
| | - Jason Atlas
- Department of Neuroscience, University of Rochester Medical Center, Rochester, New York, US
| | - Cassandra Lamantia
- Department of Neuroscience, University of Rochester Medical Center, Rochester, New York, US
| | - Ania K Majewska
- Department of Neuroscience, University of Rochester Medical Center, Rochester, New York, US.,Center for Visual Science, University of Rochester Medical Center, Rochester, New York, US
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35
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Li F, Yang BB. Non-Coding RNAs in Invadopodia: New Insights Into Cancer Metastasis. Front Oncol 2021; 11:681576. [PMID: 34290983 PMCID: PMC8287828 DOI: 10.3389/fonc.2021.681576] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 05/19/2021] [Indexed: 12/17/2022] Open
Abstract
Invadopodia are actin-rich structures and their formation is implicated in cancer invasion and metastasis. Growing evidence has shown that noncoding RNAs (ncRNAs) play important roles in pathological conditions, including tumorigenesis and metastasis. Although this is still a new area of research, ncRNAs appear to be promising biomarkers and therapeutic targets for cancer metastasis. However, understanding the roles of ncRNAs in invadopodia is still in the early stages and far from clinical application. In this mini-review, we summarize the roles of ncRNAs in invadopodia functions and discuss them in a therapeutic context. The current challenges and gaps in this field are also raised, and we provide some open questions to facilitate new ideas in targeting invadopodia in anticancer therapy.
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Affiliation(s)
- Feiya Li
- Division of Biological Sciences, Sunnybrook Research Institute, Toronto, ON, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Burton B Yang
- Division of Biological Sciences, Sunnybrook Research Institute, Toronto, ON, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
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36
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Nakazawa S, Iwasato T. Spatial organization and transitions of spontaneous neuronal activities in the developing sensory cortex. Dev Growth Differ 2021; 63:323-339. [PMID: 34166527 DOI: 10.1111/dgd.12739] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 06/21/2021] [Accepted: 06/22/2021] [Indexed: 12/30/2022]
Abstract
The sensory cortex underlies our ability to perceive and interact with the external world. Sensory perceptions are controlled by specialized neuronal circuits established through fine-tuning, which relies largely on neuronal activity during the development. Spontaneous neuronal activity is an essential driving force of neuronal circuit refinement. At early developmental stages, sensory cortices display spontaneous activities originating from the periphery and characterized by correlated firing arranged spatially according to the modality. The firing patterns are reorganized over time and become sparse, which is typical for the mature brain. This review focuses mainly on rodent sensory cortices. First, the features of the spontaneous activities during early postnatal stages are described. Then, the developmental changes in the spatial organization of the spontaneous activities and the transition mechanisms involved are discussed. The identification of the principles controlling the spatial organization of spontaneous activities in the developing sensory cortex is essential to understand the self-organization process of neuronal circuits.
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Affiliation(s)
- Shingo Nakazawa
- Laboratory of Mammalian Neural Circuits, National Institute of Genetics, Mishima, Japan.,Department of Basic Neurosciences, University of Geneva, Geneva, Switzerland
| | - Takuji Iwasato
- Laboratory of Mammalian Neural Circuits, National Institute of Genetics, Mishima, Japan.,Department of Genetics, SOKENDAI (The Graduate University for Advanced Studies), Mishima, Japan
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Davidson AM, Mejía-Gómez H, Jacobowitz M, Mostany R. Dendritic Spine Density and Dynamics of Layer 5 Pyramidal Neurons of the Primary Motor Cortex Are Elevated With Aging. Cereb Cortex 2021; 30:767-777. [PMID: 31298696 DOI: 10.1093/cercor/bhz124] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 04/17/2019] [Accepted: 05/20/2019] [Indexed: 01/04/2023] Open
Abstract
It is well established that motor impairment often occurs alongside healthy aging, leading to problems with fine motor skills and coordination. Although previously thought to be caused by neuronal death accumulating across the lifespan, it is now believed that the source of this impairment instead stems from more subtle changes in neural connectivity. The dendritic spine is a prime target for exploration of this problem because it is the postsynaptic partner of most excitatory synapses received by the pyramidal neuron, a cortical cell that carries much of the information processing load in the cerebral cortex. We repeatedly imaged the same dendrites in young adult and aged mouse motor cortex over the course of 1 month to look for differences in the baseline state of the dendritic spine population. These experiments reveal increased dendritic spine density, without obvious changes in spine clustering, occurring at the aged dendrite. Additionally, aged dendrites exhibit elevated spine turnover and stabilization alongside decreased long-term spine survival. These results suggest that at baseline the aged motor cortex may exist in a perpetual state of relative instability and attempts at compensation. This phenotype of aging may provide clues for future targets of aging-related motor impairment remediation.
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Affiliation(s)
- A M Davidson
- Department of Cell and Molecular Biology, Tulane University, New Orleans, LA 70118, USA.,Department of Pharmacology, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - H Mejía-Gómez
- Neuroscience Program, Brain Institute, Tulane University, New Orleans, LA 70118, USA.,Department of Pharmacology, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - M Jacobowitz
- Department of Pharmacology, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - R Mostany
- Department of Pharmacology, Tulane University School of Medicine, New Orleans, LA 70112, USA.,Brain Institute, Tulane University, New Orleans, LA 70118, USA
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38
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Tavosanis G. Dendrite enlightenment. Curr Opin Neurobiol 2021; 69:222-230. [PMID: 34134010 DOI: 10.1016/j.conb.2021.05.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 05/04/2021] [Accepted: 05/05/2021] [Indexed: 12/18/2022]
Abstract
Neuronal dendrites acquire complex morphologies during development. These are not just the product of cell-intrinsic developmental programs; rather they are defined in close interaction with the cellular environment. Thus, to understand the molecular cascades that yield appropriate morphologies, it is essential to investigate them in vivo, in the actual complex tissue environment encountered by the differentiating neuron in the developing animal. Particularly, genetic approaches have pointed to factors controlling dendrite differentiation in vivo. These suggest that localized and transient molecular cascades might underlie the formation and stabilization of dendrite branches with neuron type-specific characteristics. Here, I highlight the need for studies of neuronal dendrite differentiation in the animal, the challenges provided by such an approach, and the promising pathways that have recently opened.
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Affiliation(s)
- Gaia Tavosanis
- German Center for Neurodegenerative Diseases (DZNE), Venusberg-Campus 1/99, Bonn, 53127, Germany; LIMES Institute, University of Bonn, Carl-Troll-Str. 3, Bonn, 53115, Germany.
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39
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Lippman-Bell JJ, Handy M, Nieder CG, Getzfread M, Jensen FE. Altered hippocampal dendritic spine maturation after hypoxia-induced seizures in neonatal rats. Mol Cell Neurosci 2021; 113:103629. [PMID: 34015497 DOI: 10.1016/j.mcn.2021.103629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 05/10/2021] [Accepted: 05/12/2021] [Indexed: 12/01/2022] Open
Abstract
Cognitive comorbidities often follow early-life seizures (ELS), especially in the setting of autism and other neurodevelopmental syndromes. However, there is an incomplete understanding of whether neuronal and synaptic development are concomitantly dysregulated. We have previously shown that hypoxia-induced seizures (HS) in postnatal day (P)10 rats increase acute and later-life hippocampal glutamatergic neurotransmission and spontaneous recurrent seizures, and impair cognition and behavior. As dendritic spines critically regulate synaptic function, we hypothesized that ELS can induce developmentally specific changes in dendritic spine maturation. At intervals during one month following HS in P10 rats, we assessed dendritic spine development on pyramidal neurons in the stratum radiatum of hippocampal area CA1. Compared to control rats in which spine density significantly decreased from P10 to early adulthood (P38), post-seizure rats failed to show a developmental decrease in spine density, and spines from P38 post-seizure rats appeared more immature-shaped (long, thin). In addition, compared to P38 control rats, post-seizure P38 rats expressed significantly more synaptic PSD-95, a marker of mature synapses. These changes were preceded by a transient increase in hippocampal expression of cofilin phosphorylated at Ser3, representing a decrease in cofilin activity. These results suggest that early-life seizures may impair normal dendritic spine maturation and pruning in CA1 during development, resulting in an excess of less efficient synapses, via activity-dependent modification of actin-regulating proteins such as cofilin. Given that multiple neurodevelopmental disorders show similar failures in developmental spine pruning, the current findings may represent a deficit in structural plasticity that could be a component of a mechanism leading to later-life cognitive consequences associated with early-life seizures.
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Affiliation(s)
- Jocelyn J Lippman-Bell
- Department of Biomedical Sciences, Philadelphia College of Osteopathic Medicine, Philadelphia, PA, United States of America; Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States of America.
| | - Marcus Handy
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States of America
| | - Cassidy G Nieder
- Department of Biomedical Sciences, Philadelphia College of Osteopathic Medicine, Philadelphia, PA, United States of America
| | - Mollie Getzfread
- Department of Biomedical Sciences, Philadelphia College of Osteopathic Medicine, Philadelphia, PA, United States of America
| | - Frances E Jensen
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States of America.
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40
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Parallel and Serial Sensory Processing in Developing Primary Somatosensory and Motor Cortex. J Neurosci 2021; 41:3418-3431. [PMID: 33622773 DOI: 10.1523/jneurosci.2614-20.2021] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 12/23/2020] [Accepted: 02/16/2021] [Indexed: 01/21/2023] Open
Abstract
It is generally supposed that primary motor cortex (M1) receives somatosensory input predominantly via primary somatosensory cortex (S1). However, a growing body of evidence indicates that M1 also receives direct sensory input from the thalamus, independent of S1; such direct input is particularly evident at early ages before M1 contributes to motor control. Here, recording extracellularly from the forelimb regions of S1 and M1 in unanesthetized rats at postnatal day (P)8 and P12, we compared S1 and M1 responses to self-generated (i.e., reafferent) forelimb movements during active sleep and wake, and to other-generated (i.e., exafferent) forelimb movements. At both ages, reafferent responses were processed in parallel by S1 and M1; in contrast, exafferent responses were processed in parallel at P8 but serially, from S1 to M1, at P12. To further assess this developmental difference in processing, we compared exafferent responses to proprioceptive and tactile stimulation. At both P8 and P12, proprioceptive stimulation evoked parallel responses in S1 and M1, whereas tactile stimulation evoked parallel responses at P8 and serial responses at P12. Independent of the submodality of exafferent stimulation, pairs of S1-M1 units exhibited greater coactivation during active sleep than wake. These results indicate that S1 and M1 independently develop somatotopy before establishing the interactive relationship that typifies their functionality in adults.SIGNIFICANCE STATEMENT Learning any new motor task depends on the ability to use sensory information to update motor outflow. Thus, to understand motor learning, we must also understand how animals process sensory input. Primary somatosensory cortex (S1) and primary motor cortex (M1) are two interdependent structures that process sensory input throughout life. In adults, the functional relationship between S1 and M1 is well established; however, little is known about how S1 and M1 begin to transmit or process sensory information in early life. In this study, we investigate the early development of S1 and M1 as a sensory processing unit. Our findings provide new insights into the fundamental principles of sensory processing and the development of functional connectivity between these important sensorimotor structures.
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Giri S, Ranjan A, Kumar A, Amar M, Mallick BN. Rapid eye movement sleep deprivation impairs neuronal plasticity and reduces hippocampal neuronal arborization in male albino rats: Noradrenaline is involved in the process. J Neurosci Res 2021; 99:1815-1834. [PMID: 33819353 DOI: 10.1002/jnr.24838] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 03/05/2021] [Accepted: 03/13/2021] [Indexed: 12/22/2022]
Abstract
Rapid eye movement sleep (REMS) favors brain development and memory, while it is decreased in neurodegenerative diseases. REMS deprivation (REMSD) affects several physiological processes including memory consolidation; however, its detailed mechanism(s) of action was unknown. REMS reduces, while REMSD elevates noradrenaline (NA) level in the brain; the latter induces several deficiencies and disorders, including changes in neuronal cytomorphology and apoptosis. Therefore, we proposed that REMS- and REMSD-associated modulation of NA level might affect neuronal plasticity and affect brain functions. Male albino rats were REMS deprived by flower-pot method for 6 days, and its effects were compared with home cage and large platform controls as well as post-REMSD recovered and REMS-deprived prazosin (α1-adrenoceptor antagonist)-treated rats. We observed that REMSD reduced CA1 and CA3 neuronal dendritic length, branching, arborization, and spine density, while length of active zone and expressions of pre- as well as post-synaptic proteins were increased as compared to controls; interestingly, prazosin prevented most of the effects in vivo. Studies on primary culture of neurons from chick embryo brain confirmed that NA at lower concentration(s) induced neuronal branching and arborization, while higher doses were destructive. The findings support our contention that REMSD adversely affects neuronal plasticity, branching, and synaptic scaffold, which explain the underlying cytoarchitectural basis of REMSD-associated patho-physio-behavioral changes. Consolidation of findings of this study along with that of our previous reports suggest that the neuronal disintegration could be due to either withdrawal of direct protective and proliferative role of low dose of NA or indirect effect of high dose of NA or both.
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Affiliation(s)
- Shatrunjai Giri
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Amit Ranjan
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, India.,Mahatma Gandhi Central University, Motihari, Bihar, India
| | - Awanish Kumar
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Megha Amar
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, India.,Department of Psychiatry, University of California San Diego, La Jolla, CA, USA
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Yang W, Chini M, Pöpplau JA, Formozov A, Dieter A, Piechocinski P, Rais C, Morellini F, Sporns O, Hanganu-Opatz IL, Wiegert JS. Anesthetics fragment hippocampal network activity, alter spine dynamics, and affect memory consolidation. PLoS Biol 2021; 19:e3001146. [PMID: 33793545 PMCID: PMC8016109 DOI: 10.1371/journal.pbio.3001146] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 02/15/2021] [Indexed: 02/07/2023] Open
Abstract
General anesthesia is characterized by reversible loss of consciousness accompanied by transient amnesia. Yet, long-term memory impairment is an undesirable side effect. How different types of general anesthetics (GAs) affect the hippocampus, a brain region central to memory formation and consolidation, is poorly understood. Using extracellular recordings, chronic 2-photon imaging, and behavioral analysis, we monitor the effects of isoflurane (Iso), medetomidine/midazolam/fentanyl (MMF), and ketamine/xylazine (Keta/Xyl) on network activity and structural spine dynamics in the hippocampal CA1 area of adult mice. GAs robustly reduced spiking activity, decorrelated cellular ensembles, albeit with distinct activity signatures, and altered spine dynamics. CA1 network activity under all 3 anesthetics was different to natural sleep. Iso anesthesia most closely resembled unperturbed activity during wakefulness and sleep, and network alterations recovered more readily than with Keta/Xyl and MMF. Correspondingly, memory consolidation was impaired after exposure to Keta/Xyl and MMF, but not Iso. Thus, different anesthetics distinctly alter hippocampal network dynamics, synaptic connectivity, and memory consolidation, with implications for GA strategy appraisal in animal research and clinical settings.
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Affiliation(s)
- Wei Yang
- Research Group Synaptic Wiring and Information Processing, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Mattia Chini
- Institute of Developmental Neurophysiology, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Jastyn A. Pöpplau
- Institute of Developmental Neurophysiology, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Andrey Formozov
- Research Group Synaptic Wiring and Information Processing, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Alexander Dieter
- Research Group Synaptic Wiring and Information Processing, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Patrick Piechocinski
- Research Group Synaptic Wiring and Information Processing, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Cynthia Rais
- Research Group Synaptic Wiring and Information Processing, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Fabio Morellini
- Research Group Behavioral Biology, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Olaf Sporns
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana, United States of America
- Indiana University Network Science Institute, Indiana University, Bloomington, Indiana, United States of America
| | - Ileana L. Hanganu-Opatz
- Institute of Developmental Neurophysiology, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - J. Simon Wiegert
- Research Group Synaptic Wiring and Information Processing, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- * E-mail:
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43
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Zhu Y, Uytiepo M, Bushong E, Haberl M, Beutter E, Scheiwe F, Zhang W, Chang L, Luu D, Chui B, Ellisman M, Maximov A. Nanoscale 3D EM reconstructions reveal intrinsic mechanisms of structural diversity of chemical synapses. Cell Rep 2021; 35:108953. [PMID: 33826888 PMCID: PMC8354523 DOI: 10.1016/j.celrep.2021.108953] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 01/21/2021] [Accepted: 03/15/2021] [Indexed: 10/25/2022] Open
Abstract
Chemical synapses of shared cellular origins have remarkably heterogeneous structures, but how this diversity is generated is unclear. Here, we use three-dimensional (3D) electron microscopy and artificial intelligence algorithms for image processing to reconstruct functional excitatory microcircuits in the mouse hippocampus and microcircuits in which neurotransmitter signaling is permanently suppressed with genetic tools throughout the lifespan. These nanoscale analyses reveal that experience is dispensable for morphogenesis of synapses with different geometric shapes and contents of membrane organelles and that arrangement of morphologically distinct connections in local networks is stochastic. Moreover, loss of activity increases the variability in sizes of opposed pre- and postsynaptic structures without disrupting their alignments, suggesting that inherently variable weights of naive connections become progressively matched with repetitive use. These results demonstrate that mechanisms for the structural diversity of neuronal synapses are intrinsic and provide insights into how circuits essential for memory storage assemble and integrate information.
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Affiliation(s)
- Yongchuan Zhu
- Department of Neuroscience, The Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Marco Uytiepo
- Department of Neuroscience, The Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Eric Bushong
- National Center for Microscopy and Imaging Research, University of California, San Diego, CA 92037, USA; Department of Neurosciences, University of California, San Diego, School of Medicine, La Jolla, CA 92037, USA
| | - Matthias Haberl
- National Center for Microscopy and Imaging Research, University of California, San Diego, CA 92037, USA; Department of Neurosciences, University of California, San Diego, School of Medicine, La Jolla, CA 92037, USA
| | - Elizabeth Beutter
- Department of Neuroscience, The Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Frederieke Scheiwe
- Department of Neuroscience, The Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Weiheng Zhang
- Department of Neuroscience, The Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Lyanne Chang
- Department of Neuroscience, The Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Danielle Luu
- Department of Neuroscience, The Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Brandon Chui
- Department of Neuroscience, The Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Mark Ellisman
- National Center for Microscopy and Imaging Research, University of California, San Diego, CA 92037, USA; Department of Neurosciences, University of California, San Diego, School of Medicine, La Jolla, CA 92037, USA.
| | - Anton Maximov
- Department of Neuroscience, The Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037, USA.
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44
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Yusifov R, Tippmann A, Staiger JF, Schlüter OM, Löwel S. Spine dynamics of PSD-95-deficient neurons in the visual cortex link silent synapses to structural cortical plasticity. Proc Natl Acad Sci U S A 2021; 118:e2022701118. [PMID: 33649238 PMCID: PMC7958355 DOI: 10.1073/pnas.2022701118] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Critical periods (CPs) are time windows of heightened brain plasticity during which experience refines synaptic connections to achieve mature functionality. At glutamatergic synapses on dendritic spines of principal cortical neurons, the maturation is largely governed by postsynaptic density protein-95 (PSD-95)-dependent synaptic incorporation of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors into nascent AMPA-receptor silent synapses. Consequently, in mouse primary visual cortex (V1), impaired silent synapse maturation in PSD-95-deficient neurons prevents the closure of the CP for juvenile ocular dominance plasticity (jODP). A structural hallmark of jODP is increased spine elimination, induced by brief monocular deprivation (MD). However, it is unknown whether impaired silent synapse maturation facilitates spine elimination and also preserves juvenile structural plasticity. Using two-photon microscopy, we assessed spine dynamics in apical dendrites of layer 2/3 pyramidal neurons (PNs) in binocular V1 during ODP in awake adult mice. Under basal conditions, spine formation and elimination ratios were similar between PSD-95 knockout (KO) and wild-type (WT) mice. However, a brief MD affected spine dynamics only in KO mice, where MD doubled spine elimination, primarily affecting newly formed spines, and caused a net reduction in spine density similar to what has been observed during jODP in WT mice. A similar increase in spine elimination after MD occurred if PSD-95 was knocked down in single PNs of layer 2/3. Thus, structural plasticity is dictated cell autonomously by PSD-95 in vivo in awake mice. Loss of PSD-95 preserves hallmark features of spine dynamics in jODP into adulthood, revealing a functional link of PSD-95 for experience-dependent synapse maturation and stabilization during CPs.
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Affiliation(s)
- Rashad Yusifov
- Department of Systems Neuroscience, Johann Friedrich Blumenbach Institut für Zoologie und Anthropologie, Universität Göttingen, D-37075 Göttingen, Germany
- Collaborative Research Center 889, Universität Göttingen, D-37075 Göttingen, Germany
- Campus Institute for Dynamics of Biological Networks, Universität Göttingen, D-37075 Göttingen, Germany
| | - Anja Tippmann
- Department of Systems Neuroscience, Johann Friedrich Blumenbach Institut für Zoologie und Anthropologie, Universität Göttingen, D-37075 Göttingen, Germany
- Campus Institute for Dynamics of Biological Networks, Universität Göttingen, D-37075 Göttingen, Germany
| | - Jochen F Staiger
- Collaborative Research Center 889, Universität Göttingen, D-37075 Göttingen, Germany
- Institute for Neuroanatomy, University Medical Center, Universität Göttingen, D-37075 Göttingen, Germany
| | - Oliver M Schlüter
- Collaborative Research Center 889, Universität Göttingen, D-37075 Göttingen, Germany
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260
- Department of Psychiatry and Psychotherapy, University Medical Center Göttingen, Universität Göttingen, D-37075 Göttingen, Germany
| | - Siegrid Löwel
- Department of Systems Neuroscience, Johann Friedrich Blumenbach Institut für Zoologie und Anthropologie, Universität Göttingen, D-37075 Göttingen, Germany;
- Collaborative Research Center 889, Universität Göttingen, D-37075 Göttingen, Germany
- Campus Institute for Dynamics of Biological Networks, Universität Göttingen, D-37075 Göttingen, Germany
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Virtanen MA, Uvarov P, Mavrovic M, Poncer JC, Kaila K. The Multifaceted Roles of KCC2 in Cortical Development. Trends Neurosci 2021; 44:378-392. [PMID: 33640193 DOI: 10.1016/j.tins.2021.01.004] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 12/29/2020] [Accepted: 01/19/2021] [Indexed: 02/06/2023]
Abstract
KCC2, best known as the neuron-specific chloride-extruder that sets the strength and polarity of GABAergic currents during neuronal maturation, is a multifunctional molecule that can regulate cytoskeletal dynamics via its C-terminal domain (CTD). We describe the molecular and cellular mechanisms involved in the multiple functions of KCC2 and its splice variants, ranging from developmental apoptosis and the control of early network events to the formation and plasticity of cortical dendritic spines. The versatility of KCC2 actions at the cellular and subcellular levels is also evident in mature neurons during plasticity, disease, and aging. Thus, KCC2 has emerged as one of the most important molecules that shape the overall neuronal phenotype.
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Affiliation(s)
- Mari A Virtanen
- Molecular and Integrative Biosciences, University of Helsinki, 00014 Helsinki, Finland; Neuroscience Center, Helsinki Institute of Life Science, University of Helsinki, 00014 Helsinki, Finland
| | - Pavel Uvarov
- Molecular and Integrative Biosciences, University of Helsinki, 00014 Helsinki, Finland; Neuroscience Center, Helsinki Institute of Life Science, University of Helsinki, 00014 Helsinki, Finland
| | - Martina Mavrovic
- Molecular and Integrative Biosciences, University of Helsinki, 00014 Helsinki, Finland; Neuroscience Center, Helsinki Institute of Life Science, University of Helsinki, 00014 Helsinki, Finland; Department of Molecular Medicine, University of Oslo, 0372 Oslo, Norway
| | - Jean Christophe Poncer
- INSERM, UMRS 1270, 75005 Paris, France; Sorbonne Université, 75005 Paris, France; Institut du Fer à Moulin, 75005 Paris, France
| | - Kai Kaila
- Molecular and Integrative Biosciences, University of Helsinki, 00014 Helsinki, Finland; Neuroscience Center, Helsinki Institute of Life Science, University of Helsinki, 00014 Helsinki, Finland.
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46
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Cramer SW, Carter RE, Aronson JD, Kodandaramaiah SB, Ebner TJ, Chen CC. Through the looking glass: A review of cranial window technology for optical access to the brain. J Neurosci Methods 2021; 354:109100. [PMID: 33600850 DOI: 10.1016/j.jneumeth.2021.109100] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2020] [Revised: 02/07/2021] [Accepted: 02/09/2021] [Indexed: 02/07/2023]
Abstract
Deciphering neurologic function is a daunting task, requiring understanding the neuronal networks and emergent properties that arise from the interactions among single neurons. Mechanistic insights into neuronal networks require tools that simultaneously assess both single neuron activity and the consequent mesoscale output. The development of cranial window technologies, in which the skull is thinned or replaced with a synthetic optical interface, has enabled monitoring neuronal activity from subcellular to mesoscale resolution in awake, behaving animals when coupled with advanced microscopy techniques. Here we review recent achievements in cranial window technologies, appraise the relative merits of each design and discuss the future research in cranial window design.
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Affiliation(s)
- Samuel W Cramer
- Department of Neurosurgery, University of Minnesota, 420 Delaware St SE, Mayo D429, MMC 96, Twin Cities, Minneapolis, MN, 55455, USA
| | - Russell E Carter
- Department of Neuroscience, University of Minnesota, Twin Cities, Room 421, 2001 Sixth Street S.E., Minneapolis, MN, 55455 MN, USA
| | - Justin D Aronson
- Department of Neuroscience, University of Minnesota, Twin Cities, Room 421, 2001 Sixth Street S.E., Minneapolis, MN, 55455 MN, USA
| | - Suhasa B Kodandaramaiah
- Department of Mechanical Engineering, University of Minnesota, Twin Cities, MN, USA; Department of Biomedical Engineering, University of Minnesota, Twin Cities, MN, USA; Graduate Program in Neuroscience, University of Minnesota, Twin Cities, MN, USA
| | - Timothy J Ebner
- Department of Neuroscience, University of Minnesota, Twin Cities, Room 421, 2001 Sixth Street S.E., Minneapolis, MN, 55455 MN, USA.
| | - Clark C Chen
- Department of Neurosurgery, University of Minnesota, 420 Delaware St SE, Mayo D429, MMC 96, Twin Cities, Minneapolis, MN, 55455, USA.
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47
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Jamjoom AAB, Rhodes J, Andrews PJD, Grant SGN. The synapse in traumatic brain injury. Brain 2021; 144:18-31. [PMID: 33186462 PMCID: PMC7880663 DOI: 10.1093/brain/awaa321] [Citation(s) in RCA: 64] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 08/05/2020] [Accepted: 08/06/2020] [Indexed: 12/13/2022] Open
Abstract
Traumatic brain injury (TBI) is a leading cause of death and disability worldwide and is a risk factor for dementia later in life. Research into the pathophysiology of TBI has focused on the impact of injury on the neuron. However, recent advances have shown that TBI has a major impact on synapse structure and function through a combination of the immediate mechanical insult and the ensuing secondary injury processes, leading to synapse loss. In this review, we highlight the role of the synapse in TBI pathophysiology with a focus on the confluence of multiple secondary injury processes including excitotoxicity, inflammation and oxidative stress. The primary insult triggers a cascade of events in each of these secondary processes and we discuss the complex interplay that occurs at the synapse. We also examine how the synapse is impacted by traumatic axonal injury and the role it may play in the spread of tau after TBI. We propose that astrocytes play a crucial role by mediating both synapse loss and recovery. Finally, we highlight recent developments in the field including synapse molecular imaging, fluid biomarkers and therapeutics. In particular, we discuss advances in our understanding of synapse diversity and suggest that the new technology of synaptome mapping may prove useful in identifying synapses that are vulnerable or resistant to TBI.
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Affiliation(s)
- Aimun A B Jamjoom
- Centre for Clinical Brain Sciences, Chancellor's Building, Edinburgh BioQuarter, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - Jonathan Rhodes
- Anaesthesia, Critical Care and Pain Medicine, University of Edinburgh, Edinburgh EH16 4SA, UK
| | - Peter J D Andrews
- Anaesthesia, Critical Care and Pain Medicine, University of Edinburgh, Edinburgh EH16 4SA, UK
| | - Seth G N Grant
- Centre for Clinical Brain Sciences, Chancellor's Building, Edinburgh BioQuarter, University of Edinburgh, Edinburgh EH16 4SB, UK
- Simons Initiative for the Developing Brain (SIDB), Centre for Discovery Brain Sciences, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK
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Chamaa F, Darwish B, Nahas Z, Al-Chaer ED, Saadé NE, Abou-Kheir W. Long-term stimulation of the anteromedial thalamus increases hippocampal neurogenesis and spatial reference memory in adult rats. Behav Brain Res 2021; 402:113114. [PMID: 33417991 DOI: 10.1016/j.bbr.2021.113114] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 12/29/2020] [Accepted: 12/30/2020] [Indexed: 01/07/2023]
Abstract
Deep brain stimulation (DBS) has shown positive clinical results in neurodegenerative diseases. Previous work from our group showed that a single session of DBS to the anteromedial thalamic nucleus (AMN) in awake rats, increased proliferation of stem/progenitor cells in the dentate gyrus (DG) of the hippocampus. We thought to examine the effect of single versus multiple sessions of DBS to the AMN in modulating adult hippocampal neurogenesis. Rats received unilateral single session, multiple sessions or no electrical stimulation (sham) in the right AMN. Rats received 5'-bromo-2'-deoxyuridine (BrdU) injections and were followed over a period of 1 week or 4 weeks. Single session of electrical stimulation induced a 1.9-fold increase in the number of proliferating BrdU positive cells after one week from stimulation and a 1.8-fold increase at four weeks post stimulation, both in the ipsilateral DG. As for multiple sessions of stimulation, they induced a 3- fold increase that extended to the contralateral DG after 4 weeks from stimulation. Spatial reference memory was tested in the Y-maze test by examining novel arm exploration. Both single and multiple sessions of stimulation prompted an increase in novel arm exploration at week 4, while only the multiple sessions of stimulation had this effect starting from week 1. This study demonstrates that sustained activation of the AMN boosts neurogenesis and improves spatial reference memory.
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Affiliation(s)
- Farah Chamaa
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine, American University of Beirut, Beirut, Lebanon; Biological and Environmental Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Batoul Darwish
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - Ziad Nahas
- Department of Psychiatry, University of Minnesota, Minneapolis, MN, USA
| | - Elie D Al-Chaer
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - Nayef E Saadé
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - Wassim Abou-Kheir
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine, American University of Beirut, Beirut, Lebanon.
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RAB39B-mediated trafficking of the GluA2-AMPAR subunit controls dendritic spine maturation and intellectual disability-related behaviour. Mol Psychiatry 2021; 26:6531-6549. [PMID: 34035473 PMCID: PMC8760075 DOI: 10.1038/s41380-021-01155-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 04/19/2021] [Accepted: 05/04/2021] [Indexed: 12/17/2022]
Abstract
Mutations in the RAB39B gene cause X-linked intellectual disability (XLID), comorbid with autism spectrum disorders or early Parkinson's disease. One of the functions of the neuronal small GTPase RAB39B is to drive GluA2/GluA3 α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) maturation and trafficking, determining AMPAR subunit composition at glutamatergic postsynaptic neuronal terminals. Taking advantage of the Rab39b knockout murine model, we show that a lack of RAB39B affects neuronal dendritic spine refinement, prompting a more Ca2+-permeable and excitable synaptic network, which correlates with an immature spine arrangement and behavioural and cognitive alterations in adult mice. The persistence of immature circuits is triggered by increased hypermobility of the spine, which is restored by the Ca2+-permeable AMPAR antagonist NASPM. Together, these data confirm that RAB39B controls AMPAR trafficking, which in turn plays a pivotal role in neuronal dendritic spine remodelling and that targeting Ca2+-permeable AMPARs may highlight future pharmaceutical interventions for RAB39B-associated disease conditions.
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Rao MS, Mizuno H. Elucidating mechanisms of neuronal circuit formation in layer 4 of the somatosensory cortex via intravital imaging. Neurosci Res 2020; 167:47-53. [PMID: 33309867 DOI: 10.1016/j.neures.2020.10.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 09/27/2020] [Accepted: 10/01/2020] [Indexed: 12/13/2022]
Abstract
The cerebral cortex has complex yet perfectly wired neuronal circuits that are important for high-level brain functions such as perception and cognition. The rodent's somatosensory system is widely used for understanding the mechanisms of circuit formation during early developmental periods. In this review, we summarize the developmental processes of circuit formation in layer 4 of the somatosensory cortex, and we describe the molecules involved in layer 4 circuit formation and neuronal activity-dependent mechanisms of circuit formation. We also introduce the dynamic mechanisms of circuit formation in layer 4 revealed by intravital two-photon imaging technologies, which include time-lapse imaging of neuronal morphology and calcium imaging of neuronal activity in newborn mice.
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Affiliation(s)
- Madhura S Rao
- Laboratory of Multi-dimensional Imaging, International Research Center for Medical Sciences (IRCMS), Kumamoto University, Kumamoto, 860-0811, Japan; Graduate School of Medical Sciences, Kumamoto University, Kumamoto, 860-0811, Japan
| | - Hidenobu Mizuno
- Laboratory of Multi-dimensional Imaging, International Research Center for Medical Sciences (IRCMS), Kumamoto University, Kumamoto, 860-0811, Japan; Graduate School of Medical Sciences, Kumamoto University, Kumamoto, 860-0811, Japan.
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