1. Limited functional convergence of eye-specific inputs in the retinogeniculate pathway of the mouse
- Author
-
Martin H.P. Fernholz, Joel Bauer, Volker Scheuss, Simon Weiler, Mark Hübener, Tobias Rose, Tobias Bonhoeffer, and David Laubender
- Subjects
0301 basic medicine ,Retinal Ganglion Cells ,genetic structures ,Biology ,Optogenetics ,Lateral geniculate nucleus ,Functional Laterality ,Ocular dominance ,Synapse ,03 medical and health sciences ,Mice ,0302 clinical medicine ,medicine ,Animals ,Visual Pathways ,Vision, Binocular ,General Neuroscience ,Geniculate Bodies ,eye diseases ,Monocular deprivation ,030104 developmental biology ,medicine.anatomical_structure ,Visual cortex ,nervous system ,Retinal ganglion cell ,sense organs ,Neuron ,Neuroscience ,030217 neurology & neurosurgery - Abstract
Summary Segregation of retinal ganglion cell (RGC) axons by type and eye of origin is considered a hallmark of dorsal lateral geniculate nucleus (dLGN) structure. However, recent anatomical studies have shown that neurons in mouse dLGN receive input from multiple RGC types of both retinae. Whether convergent input leads to relevant functional interactions is unclear. We studied functional eye-specific retinogeniculate convergence using dual-color optogenetics in vitro. dLGN neurons were strongly dominated by input from one eye. Most neurons received detectable input from the non-dominant eye, but this input was weak, with a prominently reduced AMPAR:NMDAR ratio. Consistent with this, only a small fraction of thalamocortical neurons was binocular in vivo across visual stimuli and cortical projection layers. Anatomical overlap between RGC axons and dLGN neuron dendrites alone did not explain the strong bias toward monocularity. We conclude that functional eye-specific input selection and refinement limit convergent interactions in dLGN, favoring monocularity.
- Published
- 2020