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Kozlowski C, Hadyniak SE, Kay JN. Retinal neurons establish mosaic patterning by excluding homotypic somata from their dendritic territories. Cell Rep 2024; 43:114615. [PMID: 39133615 DOI: 10.1016/j.celrep.2024.114615] [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: 11/30/2023] [Revised: 06/01/2024] [Accepted: 07/24/2024] [Indexed: 08/21/2024] Open
Abstract
In vertebrate retina, individual neurons of the same type are distributed regularly across the tissue in a pattern known as a mosaic. Establishment of mosaics during development requires cell-cell repulsion among homotypic neurons, but the mechanisms underlying this repulsion remain unknown. Here, we show that two mouse retinal cell types, OFF and ON starburst amacrine cells, establish mosaic spacing by using their dendritic arbors to repel neighboring homotypic somata. Using transgenic tools and single-cell labeling, we identify a developmental period when starburst somata are contacted by neighboring starburst dendrites; these serve to exclude somata from settling within the neighbor's dendritic territory. Dendrite-soma exclusion is mediated by MEGF10, a cell-surface molecule required for starburst mosaic patterning. Our results implicate dendrite-soma exclusion as a key mechanism underlying starburst mosaic spacing and raise the possibility that this could be a general mechanism for mosaic patterning across many cell types and species.
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Affiliation(s)
- Christopher Kozlowski
- Departments of Neurobiology, Ophthalmology, and Cell Biology, Duke University School of Medicine, Durham, NC 27710, USA
| | - Sarah E Hadyniak
- Departments of Neurobiology, Ophthalmology, and Cell Biology, Duke University School of Medicine, Durham, NC 27710, USA
| | - Jeremy N Kay
- Departments of Neurobiology, Ophthalmology, and Cell Biology, Duke University School of Medicine, Durham, NC 27710, USA.
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He L, Wang W, Ma L, Huang T. Optimization-Based Pairwise Interaction Point Process (O-PIPP): A Precise and Universal Retinal Mosaic Modeling Approach. Invest Ophthalmol Vis Sci 2024; 65:39. [PMID: 39042401 PMCID: PMC11268446 DOI: 10.1167/iovs.65.8.39] [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: 09/05/2023] [Accepted: 06/25/2024] [Indexed: 07/24/2024] Open
Abstract
Purpose A retinal mosaic, the spatial organization of a population of homotypic neurons, is thought to sample a specific visual feature into the feedforward visual pathway. The purpose of this study was to propose a universal modeling approach for precisely generating retinal mosaics and overcoming the limitations of previous models, especially in modeling abnormal mosaic patterns under disease conditions. Methods Here, we developed the optimization-based pairwise interaction point process (O-PIPP). It incorporates optimization techniques into previous simulation approaches, enabling directional control of the simulation process according to the user-designed optimization target. For the convenience of the community, we implemented the O-PIPP approach into a Python package and a website application. Results We showed that the O-PIPP can generate more precise neural spatial patterns of healthy and diseased mosaics compared to previous phenomenological approaches. Notably, through modeling the retinal neural circuitry with O-PIPP-simulated retinitis pigmentosa cone mosaics, we elucidated how the cone mosaic rearrangement impacted the information processing of ganglion cells. Conclusions The O-PIPP provides a precise and universal tool to simulate realistic mosaics, which could help to investigate the function of retinal mosaics in vision.
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Affiliation(s)
- Liuyuan He
- National Key Laboratory for Multimedia Information Processing, School of Computer Science, Peking University, Beijing, China
- National Biomedical Imaging Center, College of Future Technology, Peking University, Beijing, China
| | - Wenyao Wang
- National Biomedical Imaging Center, College of Future Technology, Peking University, Beijing, China
| | - Lei Ma
- National Key Laboratory for Multimedia Information Processing, School of Computer Science, Peking University, Beijing, China
- National Biomedical Imaging Center, College of Future Technology, Peking University, Beijing, China
| | - Tiejun Huang
- National Key Laboratory for Multimedia Information Processing, School of Computer Science, Peking University, Beijing, China
- National Biomedical Imaging Center, College of Future Technology, Peking University, Beijing, China
- Beijing Academy of Artificial Intelligence, Beijing, China
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Friedrichsen K, Hsiang JC, Lin CI, McCoy L, Valkova K, Kerschensteiner D, Morgan JL. Subcellular pathways through VGluT3-expressing mouse amacrine cells provide locally tuned object-motion-selective signals in the retina. Nat Commun 2024; 15:2965. [PMID: 38580652 PMCID: PMC10997783 DOI: 10.1038/s41467-024-46996-0] [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: 06/19/2023] [Accepted: 03/15/2024] [Indexed: 04/07/2024] Open
Abstract
VGluT3-expressing mouse retinal amacrine cells (VG3s) respond to small-object motion and connect to multiple types of bipolar cells (inputs) and retinal ganglion cells (RGCs, outputs). Because these input and output connections are intermixed on the same dendrites, making sense of VG3 circuitry requires comparing the distribution of synapses across their arbors to the subcellular flow of signals. Here, we combine subcellular calcium imaging and electron microscopic connectomic reconstruction to analyze how VG3s integrate and transmit visual information. VG3s receive inputs from all nearby bipolar cell types but exhibit a strong preference for the fast type 3a bipolar cells. By comparing input distributions to VG3 dendrite responses, we show that VG3 dendrites have a short functional length constant that likely depends on inhibitory shunting. This model predicts that RGCs that extend dendrites into the middle layers of the inner plexiform encounter VG3 dendrites whose responses vary according to the local bipolar cell response type.
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Affiliation(s)
- Karl Friedrichsen
- Department of Ophthalmology and Visual Sciences, Washington University in St. Louis, St. Louis, MO, USA
- Department of Neuroscience, Washington University in St. Louis, St. Louis, MO, USA
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA
- Graduate Program in Neuroscience, Washington University in St. Louis, St. Louis, USA
| | - Jen-Chun Hsiang
- Department of Ophthalmology and Visual Sciences, Washington University in St. Louis, St. Louis, MO, USA
- Department of Neuroscience, Washington University in St. Louis, St. Louis, MO, USA
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA
- Graduate Program in Neuroscience, Washington University in St. Louis, St. Louis, USA
| | - Chin-I Lin
- Department of Ophthalmology and Visual Sciences, Washington University in St. Louis, St. Louis, MO, USA
- Department of Neuroscience, Washington University in St. Louis, St. Louis, MO, USA
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA
- Graduate Program in Neuroscience, Washington University in St. Louis, St. Louis, USA
| | - Liam McCoy
- Department of Ophthalmology and Visual Sciences, Washington University in St. Louis, St. Louis, MO, USA
- Department of Neuroscience, Washington University in St. Louis, St. Louis, MO, USA
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Katia Valkova
- Department of Ophthalmology and Visual Sciences, Washington University in St. Louis, St. Louis, MO, USA
- Department of Neuroscience, Washington University in St. Louis, St. Louis, MO, USA
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Daniel Kerschensteiner
- Department of Ophthalmology and Visual Sciences, Washington University in St. Louis, St. Louis, MO, USA.
- Department of Neuroscience, Washington University in St. Louis, St. Louis, MO, USA.
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA.
| | - Josh L Morgan
- Department of Ophthalmology and Visual Sciences, Washington University in St. Louis, St. Louis, MO, USA.
- Department of Neuroscience, Washington University in St. Louis, St. Louis, MO, USA.
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA.
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Kozlowski C, Hadyniak SE, Kay JN. Retinal neurons establish mosaic patterning by excluding homotypic somata from their dendritic territory. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.17.567616. [PMID: 38014021 PMCID: PMC10680827 DOI: 10.1101/2023.11.17.567616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
In vertebrate retina, individual neurons of the same type are distributed regularly across the tissue in a pattern known as a mosaic. Establishment of mosaics during development requires cell-cell repulsion among homotypic neurons, but the mechanisms underlying this repulsion remain unknown. Here we show that two mouse retinal cell types, OFF and ON starburst amacrine cells, establish mosaic spacing by using their dendritic arbors to repel neighboring homotypic somata. Using newly-generated transgenic tools and single cell labeling, we identify a transient developmental period when starburst somata receive extensive contacts from neighboring starburst dendrites; these serve to exclude somata from settling within the neighbor's dendritic territory. Dendrite-soma exclusion is mediated by MEGF10, a cell-surface molecule required for starburst mosaic patterning. Our results implicate dendrite-soma exclusion as a key mechanism underlying starburst mosaic spacing, and suggest that this could be a general mechanism for mosaic patterning across many cell types and species.
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Affiliation(s)
- Christopher Kozlowski
- Departments of Neurobiology, Ophthalmology, and Cell Biology, Duke University School of Medicine, Durham, NC 27710 USA
| | - Sarah E Hadyniak
- Departments of Neurobiology, Ophthalmology, and Cell Biology, Duke University School of Medicine, Durham, NC 27710 USA
| | - Jeremy N Kay
- Departments of Neurobiology, Ophthalmology, and Cell Biology, Duke University School of Medicine, Durham, NC 27710 USA
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Keeley PW, Patel SS, Reese BE. Cell numbers, cell ratios, and developmental plasticity in the rod pathway of the mouse retina. J Anat 2023; 243:204-222. [PMID: 35292986 PMCID: PMC10335380 DOI: 10.1111/joa.13653] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 02/07/2022] [Accepted: 02/28/2022] [Indexed: 11/29/2022] Open
Abstract
The precise specification of cellular fate is thought to ensure the production of the correct number of neurons within a population. Programmed cell death may be an additional mechanism controlling cell number, believed to refine the proper ratio of pre- to post-synaptic neurons for a given species. Here, we consider the size of three different neuronal populations in the rod pathway of the mouse retina: rod photoreceptors, rod bipolar cells, and AII amacrine cells. Across a collection of 28 different strains of mice, large variation in the numbers of all three cell types is present. The variation in their numbers is not correlated, so that the ratio of rods to rod bipolar cells, as well as rod bipolar cells to AII amacrine cells, varies as well. Establishing connectivity between such variable pre- and post-synaptic populations relies upon plasticity that modulates process outgrowth and morphological differentiation, which we explore experimentally for both rod bipolar and AII amacrine cells in a mouse retina with elevated numbers of each cell type. While both rod bipolar dendritic and axonal arbors, along with AII lobular arbors, modulate their areal size in relation to local homotypic cell densities, the dendritic appendages of the AII amacrine cells do not. Rather, these processes exhibit a different form of plasticity, regulating the branching density of their overlapping arbors. Each form of plasticity should ensure uniformity in retinal coverage in the presence of the independent specification of afferent and target cell number.
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Affiliation(s)
- Patrick W. Keeley
- Neuroscience Research InstituteUniversity of California, Santa BarbaraSanta BarbaraCaliforniaUSA
| | - Shivam S. Patel
- Neuroscience Research InstituteUniversity of California, Santa BarbaraSanta BarbaraCaliforniaUSA
| | - Benjamin E. Reese
- Neuroscience Research InstituteUniversity of California, Santa BarbaraSanta BarbaraCaliforniaUSA
- Department of Psychological & Brain SciencesUniversity of California, Santa BarbaraSanta BarbaraCaliforniaUSA
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Pomaville MB, Wright KM. Follicle-innervating Aδ-low threshold mechanoreceptive neurons form receptive fields through homotypic competition. Neural Dev 2023; 18:2. [PMID: 37106422 PMCID: PMC10134579 DOI: 10.1186/s13064-023-00170-2] [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: 09/23/2022] [Accepted: 04/20/2023] [Indexed: 04/29/2023] Open
Abstract
The mammalian somatosensory system is comprised of multiple neuronal populations that form specialized, highly organized sensory endings in the skin. The organization of somatosensory endings is essential to their functions, yet the mechanisms which regulate this organization remain unclear. Using a combination of genetic and molecular labeling approaches, we examined the development of mouse hair follicle-innervating low-threshold mechanoreceptors (LTMRs) and explored competition for innervation targets as a mechanism involved in the patterning of their receptive fields. We show that follicle innervating neurons are present in the skin at birth and that LTMR receptive fields gradually add follicle-innervating endings during the first two postnatal weeks. Using a constitutive Bax knockout to increase the number of neurons in adult animals, we show that two LTMR subtypes have differential responses to an increase in neuronal population size: Aδ-LTMR neurons shrink their receptive fields to accommodate the increased number of neurons innervating the skin, while C-LTMR neurons do not. Our findings suggest that competition for hair follicles to innervate plays a role in the patterning and organization of follicle-innervating LTMR neurons.
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Affiliation(s)
- Matthew B Pomaville
- Vollum Institute, Oregon Health and Science University, Portland, OR, 97239, USA
- Department of Cell, Developmental, and Cancer Biology, Cell and Developmental Biology Graduate Program, Oregon Health and Science University, Portland, OR, 97239, USA
| | - Kevin M Wright
- Vollum Institute, Oregon Health and Science University, Portland, OR, 97239, USA.
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Risner ML, Pasini S, McGrady NR, Calkins DJ. Bax Contributes to Retinal Ganglion Cell Dendritic Degeneration During Glaucoma. Mol Neurobiol 2022; 59:1366-1380. [PMID: 34984584 PMCID: PMC8882107 DOI: 10.1007/s12035-021-02675-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 11/30/2021] [Indexed: 12/14/2022]
Abstract
The BCL-2 (B-cell lymphoma-2) family of proteins contributes to mitochondrial-based apoptosis in models of neurodegeneration, including glaucomatous optic neuropathy (glaucoma), which degrades the retinal ganglion cell (RGC) axonal projection to the visual brain. Glaucoma is commonly associated with increased sensitivity to intraocular pressure (IOP) and involves a proximal program that leads to RGC dendritic pruning and a distal program that underlies axonopathy in the optic projection. While genetic deletion of the Bcl2-associated X protein (Bax-/-) prolongs RGC body survival in models of glaucoma and optic nerve trauma, axonopathy persists, thus raising the question of whether dendrites and the RGC light response are protected. Here, we used an inducible model of glaucoma in Bax-/- mice to determine if Bax contributes to RGC dendritic degeneration. We performed whole-cell recordings and dye filling in RGCs signaling light onset (αON-Sustained) and offset (αOFF-Sustained). We recovered RGC dendritic morphologies by confocal microscopy and analyzed dendritic arbor complexity and size. Additionally, we assessed RGC axon function by measuring anterograde axon transport of cholera toxin subunit B to the superior colliculus and behavioral spatial frequency threshold (i.e., spatial acuity). We found 1 month of IOP elevation did not cause significant RGC death in either WT or Bax-/- retinas. However, IOP elevation reduced dendritic arbor complexity of WT αON-Sustained and αOFF-Sustained RGCs. In the absence of Bax, αON- and αOFF-Sustained RGC dendritic arbors remained intact following IOP elevation. In addition to dendrites, neuroprotection by Bax-/- generalized to αON-and αOFF-Sustained RGC light- and current-evoked responses. Both anterograde axon transport and spatial acuity declined during IOP elevation in WT and Bax-/- mice. Collectively, our results indicate Bax contributes to RGC dendritic degeneration and distinguishes the proximal and distal neurodegenerative programs involved during the progression of glaucoma.
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Affiliation(s)
- Michael L Risner
- Vanderbilt Eye Institute, Department of Ophthalmology and Visual Sciences, Vanderbilt University Medical Center, AA7103 MCN/VUIIS, 1161 21st Ave. S., Nashville, TN, 37232, USA
| | - Silvia Pasini
- Vanderbilt Eye Institute, Department of Ophthalmology and Visual Sciences, Vanderbilt University Medical Center, AA7103 MCN/VUIIS, 1161 21st Ave. S., Nashville, TN, 37232, USA
| | - Nolan R McGrady
- Vanderbilt Eye Institute, Department of Ophthalmology and Visual Sciences, Vanderbilt University Medical Center, AA7103 MCN/VUIIS, 1161 21st Ave. S., Nashville, TN, 37232, USA
| | - David J Calkins
- Vanderbilt Eye Institute, Department of Ophthalmology and Visual Sciences, Vanderbilt University Medical Center, AA7103 MCN/VUIIS, 1161 21st Ave. S., Nashville, TN, 37232, USA.
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