1
|
Aloni E, Tibi M, Hochgerner H, Zeisel A. Sexual dimorphism in synaptic inputs to the mouse amygdala and orbital cortex. Front Neurosci 2023; 17:1258284. [PMID: 37901417 PMCID: PMC10601666 DOI: 10.3389/fnins.2023.1258284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 09/21/2023] [Indexed: 10/31/2023] Open
Abstract
The medial amygdala (MeA) is a sexually dimorphic brain region that regulates fear responses, emotional memories, and social behaviors. It is known to be larger and contains more cells in males. The MeA integrates information through input connections from olfactory regions, bed nucleus of the stria terminalis, ventral hippocampus, and thalamic and hypothalamic structures. We hypothesize that in addition to the size differences, there are differences in regional connectivity between the sexes. In this study, we utilized G-deleted rabies monosynaptic retrograde tracing to compare amygdala presynaptic cells in male and female whole mouse brains. We report differences in connection patterns to the amygdala, with higher overall connectivity (presynaptic per starter) in males and a larger fraction of inputs originating from the bed nucleus of the stria terminalis, lateral septum, and medial preoptic area. Furthermore, we examined input connections to the orbital cortex (ORB), a brain region shown to be larger in volume in females, and found the opposite trend, where females had more total inputs. Together, our findings extend the evidence for sexual dimorphism in the brain to the neuronal wiring pattern, with likely impacts on behavior and disease susceptibility.
Collapse
Affiliation(s)
| | | | | | - Amit Zeisel
- Faculty of Biotechnology and Food Engineering, Technion - Israel Institute of Technology, Haifa, Israel
| |
Collapse
|
2
|
Elkind D, Hochgerner H, Aloni E, Shental N, Zeisel A. Sex-, strain and lateral differences in brain cytoarchitecture across a large mouse population. eLife 2023; 12:82376. [PMID: 37144870 DOI: 10.7554/elife.82376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 05/04/2023] [Indexed: 05/06/2023] Open
Abstract
The mouse brain is by far the most intensively studied among mammalian brains, yet basic measures of its cytoarchitecture remain obscure. For example, quantifying cell numbers, and the interplay of sex-, strain-, and individual variability in cell density and volume is out of reach for many regions. The Allen Mouse Brain Connectivity project produces high-resolution full brain images of hundreds of brains. Although these were created for a different purpose, they reveal details of neuroanatomy and cytoarchitecture. Here, we used this population to systematically characterize cell density and volume for each anatomical unit in the mouse brain. We developed a deep neural network-based segmentation pipeline that uses the auto-fluorescence intensities of images to segment cell nuclei even within the densest regions, such as the dentate gyrus. We applied our pipeline to 507 brains of males and females from C57BL/6J and FVB.CD1 strains. Globally, we found that increased overall brain volume does not result in uniform expansion across all regions. Moreover, region-specific density changes are often negatively correlated with the volume of the region, therefore cell count does not scale linearly with volume. Many regions, including layer 2/3 across several cortical areas, showed distinct lateral bias. We identified strain-specific or sex-specific differences. For example, males tended to have more cells in extended amygdala and hypothalamic regions (MEA, BST, BLA, BMA, and LPO, AHN) while females had more cells in the orbital cortex (ORB). Yet, inter-individual variability was always greater than the effect size of a single qualifier. We provide the results of this analysis as an accessible resource for the community.
Collapse
Affiliation(s)
- David Elkind
- Department of Computer Science, Open University of Israel, Raanana, Israel
| | - Hannah Hochgerner
- Faculty of Biotechnology and Food Engineering, Technion - Israel Institute of Technology, Haifa, Israel
| | - Etay Aloni
- Faculty of Biotechnology and Food Engineering, Technion - Israel Institute of Technology, Haifa, Israel
| | - Noam Shental
- Department of Computer Science, Open University of Israel, Raanana, Israel
| | - Amit Zeisel
- Faculty of Biotechnology and Food Engineering, Technion - Israel Institute of Technology, Haifa, Israel
| |
Collapse
|
3
|
Aloni E, Verbitsky S, Kushnireva L, Korkotian E, Segal M. Increased excitability of hippocampal neurons in mature synaptopodin-knockout mice. Brain Struct Funct 2021; 226:2459-2466. [PMID: 34291334 DOI: 10.1007/s00429-021-02346-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 07/14/2021] [Indexed: 11/28/2022]
Abstract
Synaptopodin (SP) is localized within the spine apparatus, an enigmatic structure located in the neck of spines of central excitatory neurons. It serves as a link between the spine head, where the synapse is located, and the endoplasmic reticulum (ER) in the parent dendrite. SP is also located in the axon initial segment, in association with the cisternal organelle, another structure related to the endoplasmic reticulum. Extensive research using SP knockout (SPKO) mice suggest that SP has a pivotal role in structural and functional plasticity. Consequently, young adult SPKO mice were shown to be deficient in cognitive functions, and in ability to undergo long-term potentiation of reactivity to afferent stimulation. However, although SP expresses differently during maturation, its role in synaptic and intrinsic neuronal mechanisms in adult SPKO mice is still unclear. To address this knowledge gap we analyzed hippocampus bulk mRNA in SPKO mice, and we recorded the activity of CA1 neurons in the mouse hippocampus slice, with both extracellular and patch recording methods. Electrophysiologically, SPKO cells in CA1 region of the dorsal hippocampus were more excitable than wild type (wt) ones. In addition, exposure of mice to a complex environment caused a higher proportion of arc-expressing cells in SPKO than in wt mice hippocampus. These experiments indicate that higher excitability and higher expression of arc staining may reflect SP deficiency in the hippocampus of adult SPKO mice.
Collapse
Affiliation(s)
- E Aloni
- Department of Neurobiology, Weizmann Institute, 76100, Rehovot, Israel
| | - S Verbitsky
- Department of Neurobiology, Weizmann Institute, 76100, Rehovot, Israel
| | - L Kushnireva
- Department of Neurobiology, Weizmann Institute, 76100, Rehovot, Israel
| | - E Korkotian
- Department of Neurobiology, Weizmann Institute, 76100, Rehovot, Israel
| | - M Segal
- Department of Neurobiology, Weizmann Institute, 76100, Rehovot, Israel.
| |
Collapse
|
4
|
Aloni E, Ruggiero A, Gross A, Segal M. Learning Deficits in Adult Mitochondria Carrier Homolog 2 Forebrain Knockout Mouse. Neuroscience 2018; 394:156-163. [PMID: 30401654 DOI: 10.1016/j.neuroscience.2018.10.035] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 10/15/2018] [Accepted: 10/17/2018] [Indexed: 02/02/2023]
Abstract
Mitochondrial Carrier Homolog 2 (MTCH2) acts as a receptor for the BH3 interacting-domain death agonist (BID) in the mitochondrial outer membrane. Loss of MTCH2 affects mitochondria energy metabolism and function. MTCH2 forebrain conditional KO (MTCH2 BKO) display a deficit in hippocampus-dependent cognitive functions. Here we study age-related MTCH2 BKO behavioral and electrophysiological aspects of hippocampal functions. MTCH2 BKO exhibit impaired spatial but not motor learning and an impairment in long-term potentiation (LTP) in hippocampal slices. Moreover, MTCH2 BKO express an increase in activated microglia, in addition to a reduction in neuron density in the hippocampus, but do not express amyloid-β plaques or neurofibrillary tangles. These results highlight the role of mitochondria in the normal hippocampus-dependent memory formation.
Collapse
Affiliation(s)
- Etay Aloni
- Department of Neurobiology, The Weizmann Institute, Rehovot 76100, Israel
| | - Antonella Ruggiero
- Department of Biological Regulation, The Weizmann Institute, Rehovot 76100, Israel
| | - Atan Gross
- Department of Biological Regulation, The Weizmann Institute, Rehovot 76100, Israel
| | - Menahem Segal
- Department of Neurobiology, The Weizmann Institute, Rehovot 76100, Israel.
| |
Collapse
|
5
|
Ruggiero A, Aloni E, Korkotian E, Zaltsman Y, Oni-Biton E, Kuperman Y, Tsoory M, Shachnai L, Levin-Zaidman S, Brenner O, Segal M, Gross A. Loss of forebrain MTCH2 decreases mitochondria motility and calcium handling and impairs hippocampal-dependent cognitive functions. Sci Rep 2017; 7:44401. [PMID: 28276496 PMCID: PMC5343590 DOI: 10.1038/srep44401] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 02/07/2017] [Indexed: 12/23/2022] Open
Abstract
Mitochondrial Carrier Homolog 2 (MTCH2) is a novel regulator of mitochondria metabolism, which was recently associated with Alzheimer’s disease. Here we demonstrate that deletion of forebrain MTCH2 increases mitochondria and whole-body energy metabolism, increases locomotor activity, but impairs motor coordination and balance. Importantly, mice deficient in forebrain MTCH2 display a deficit in hippocampus-dependent cognitive functions, including spatial memory, long term potentiation (LTP) and rates of spontaneous excitatory synaptic currents. Moreover, MTCH2-deficient hippocampal neurons display a deficit in mitochondria motility and calcium handling. Thus, MTCH2 is a critical player in neuronal cell biology, controlling mitochondria metabolism, motility and calcium buffering to regulate hippocampal-dependent cognitive functions.
Collapse
Affiliation(s)
- Antonella Ruggiero
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Etay Aloni
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Eduard Korkotian
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Yehudit Zaltsman
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Efrat Oni-Biton
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Yael Kuperman
- Department of Veterinary Resources, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Michael Tsoory
- Department of Veterinary Resources, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Liat Shachnai
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Smadar Levin-Zaidman
- Department of Chemical research Support, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Ori Brenner
- Department of Veterinary Resources, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Menahem Segal
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Atan Gross
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot 7610001, Israel
| |
Collapse
|
6
|
Aloni E, Shapira M, Eldar-Finkelman H, Barnea A. GSK-3β Inhibition Affects Singing Behavior and Neurogenesis in Adult Songbirds. Brain Behav Evol 2015; 85:233-44. [PMID: 26065821 DOI: 10.1159/000382029] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 04/01/2015] [Indexed: 11/19/2022]
Abstract
GSK-3 (glycogen synthase kinase-3) is a serine/threonine kinase which is a critical regulator in neuronal signaling, cognition, and behavior. We have previously shown that unlike other vertebrates that harbor both α and β GSK-3 genes, the α gene is missing in birds. Therefore, birds can be used as a new animal model to study the roles of GSK-3β in behavior and in regulating adult neurogenesis. In the present study, we inhibited GSK-3β in brains of adult male zebra finches (Taeniopygia guttata) and accordingly investigated how this inhibition affects behavior and cell proliferation. Our results show that GSK-3 inhibition: (1) affects specific aspects of singing behavior, which might be related to social interactions in birds, and (2) differentially affects cell proliferation in various parts of the ventricular zone. Taken together, our study demonstrates a role of GSK-3β in regulating singing behavior and neuronal proliferation in birds and highlights the importance of GSK-3β in modulating cognitive abilities as well as social behavior.
Collapse
Affiliation(s)
- Etay Aloni
- Department of Human Molecular Genetics and Biochemistry, Tel Aviv University, Tel Aviv, Israel
| | | | | | | |
Collapse
|
7
|
Aloni R, Aloni E, Langhans M, Ullrich CI. Role of cytokinin and auxin in shaping root architecture: regulating vascular differentiation, lateral root initiation, root apical dominance and root gravitropism. Ann Bot 2006; 97:883-93. [PMID: 16473866 PMCID: PMC2803412 DOI: 10.1093/aob/mcl027] [Citation(s) in RCA: 293] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2005] [Revised: 09/12/2005] [Accepted: 11/30/2005] [Indexed: 05/06/2023]
Abstract
BACKGROUND AND AIMS Development and architecture of plant roots are regulated by phytohormones. Cytokinin (CK), synthesized in the root cap, promotes cytokinesis, vascular cambium sensitivity, vascular differentiation and root apical dominance. Auxin (indole-3-acetic acid, IAA), produced in young shoot organs, promotes root development and induces vascular differentiation. Both IAA and CK regulate root gravitropism. The aims of this study were to analyse the hormonal mechanisms that induce the root's primary vascular system, explain how differentiating-protoxylem vessels promote lateral root initiation, propose the concept of CK-dependent root apical dominance, and visualize the CK and IAA regulation of root gravitropiosm. KEY ISSUES The hormonal analysis and proposed mechanisms yield new insights and extend previous concepts: how the radial pattern of the root protoxylem vs. protophloem strands is induced by alternating polar streams of high IAA vs. low IAA concentrations, respectively; how differentiating-protoxylem vessel elements stimulate lateral root initiation by auxin-ethylene-auxin signalling; and how root apical dominance is regulated by the root-cap-synthesized CK, which gives priority to the primary root in competition with its own lateral roots. CONCLUSIONS CK and IAA are key hormones that regulate root development, its vascular differentiation and root gravitropism; these two hormones, together with ethylene, regulate lateral root initiation.
Collapse
Affiliation(s)
- R Aloni
- Department of Plant Sciences, Tel Aviv University, Tel Aviv 69978, Israel.
| | | | | | | |
Collapse
|