Institute of Biomedical Sciences
Determining the role of pre-synaptic NMDA Receptors in retinofugal topographic map formation
Poster Number
24
Document Type
Poster
Status
Graduate Student - Doctoral
Abstract Category
Neuroscience
Keywords
NMDA Receptor, Pre-synaptic, Superior Colliculus, Dorsal Lateral Geniculate Nucleus, Topography
Publication Date
Spring 2018
Abstract
Efficient processing of sensory information is a critical function of the nervous system. Deficits in sensory processing and integration are commonly seen in neurodevelopmental disorders such as autism and fragile X syndrome. In the visual system, neurons are organized topographically, such that neighboring neurons monitor adjacent regions of space; retinal ganglion cells (RGCs) project topographically to the superior colliculus (SC) and dorsal lateral geniculate nucleus (dLGN). The establishment of topography in both the SC and the dLGN is dependent on spontaneous correlated activity. However, the mechanisms by which activity mediates topographic map formation remain uncertain. Previous studies suggest that N-methyl-D-aspartate receptors (NMDARs) play a critical role in the establishment of topography by RGCs; however, it is unclear if they are required pre- or post-synaptically. To determine the role of pre-synaptic NMDARs in retinofugal topographic map formation, we used a conditional genetic strategy to specifically ablate NMDAR function in RGCs. We focally labeled RGCs and visualized the termination zone (TZ) of their projections in the SC and dLGN. Our data suggests that there was no change in TZ size in adult mice. To determine if eye specific segregation was disrupted in these animals, retinogeniculate projections were visualized with cholera toxin beta. Both adult and mouse pups showed no significant difference in eye-specific lamination at various ages. Together, these data suggest that retinogeniculate and retinocollicular topographic map formation do not require pre-synaptic NMDAR activity.
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Open Access
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Determining the role of pre-synaptic NMDA Receptors in retinofugal topographic map formation
Efficient processing of sensory information is a critical function of the nervous system. Deficits in sensory processing and integration are commonly seen in neurodevelopmental disorders such as autism and fragile X syndrome. In the visual system, neurons are organized topographically, such that neighboring neurons monitor adjacent regions of space; retinal ganglion cells (RGCs) project topographically to the superior colliculus (SC) and dorsal lateral geniculate nucleus (dLGN). The establishment of topography in both the SC and the dLGN is dependent on spontaneous correlated activity. However, the mechanisms by which activity mediates topographic map formation remain uncertain. Previous studies suggest that N-methyl-D-aspartate receptors (NMDARs) play a critical role in the establishment of topography by RGCs; however, it is unclear if they are required pre- or post-synaptically. To determine the role of pre-synaptic NMDARs in retinofugal topographic map formation, we used a conditional genetic strategy to specifically ablate NMDAR function in RGCs. We focally labeled RGCs and visualized the termination zone (TZ) of their projections in the SC and dLGN. Our data suggests that there was no change in TZ size in adult mice. To determine if eye specific segregation was disrupted in these animals, retinogeniculate projections were visualized with cholera toxin beta. Both adult and mouse pups showed no significant difference in eye-specific lamination at various ages. Together, these data suggest that retinogeniculate and retinocollicular topographic map formation do not require pre-synaptic NMDAR activity.