Visual space is represented by nonmatching topographies of distinct mouse retinal ganglion cell types.
The distributions of neurons in sensory circuits display ordered spatial patterns arranged to enhance or encode specific regions or features of the external environment. Indeed, visual space is not sampled uniformly across the vertebrate retina. Retinal ganglion cell (RGC) density increases and dendritic arbor size decreases toward retinal locations with higher sampling frequency, such as the fovea in primates and area centralis in carnivores [1]. In these locations, higher acuity at the level of individual cells is obtained because the receptive field center of a RGC corresponds approximately to the spatial extent of its dendritic arbor [2, 3]. For most species, structurally and functionally distinct RGC types appear to have similar topographies, collectively scaling their cell densities and arbor sizes toward the same retinal location [4]. Thus, visual space is represented across the retina in parallel by multiple distinct circuits [5]. In contrast, we find a population of mouse RGCs, known as alpha or alpha-like [6], that displays a nasal-to-temporal gradient in cell density, size, and receptive fields, which facilitates enhanced visual sampling in frontal visual fields. The distribution of alpha-like RGCs contrasts with other known mouse RGC types and suggests that, unlike most mammals, RGC topographies in mice are arranged to sample space differentially.
Graduate Program in Neurobiology and Behavior, University of Washington, Seattle, WA 98195, USA; Department of Biological Structure, University of Washington, Seattle, WA 98195, USA.
Adam
A
Bleckert
Department of Physiology and Biophysics, University of Washington, Seattle, WA 98195, USA.
Gregory W
GW
Schwartz
Graduate Program in Neurobiology and Behavior, University of Washington, Seattle, WA 98195, USA; Department of Physiology and Biophysics, University of Washington, Seattle, WA 98195, USA.
Maxwell H
MH
Turner
Department of Physiology and Biophysics, University of Washington, Seattle, WA 98195, USA; Howard Hughes Medical Institute, Seattle, WA 98195, USA.
Fred
F
Rieke
Department of Biological Structure, University of Washington, Seattle, WA 98195, USA. Electronic address: wongr2@uw.edu.
Rachel O L
RO
Wong
D000818:Animals; D002452:Cell Count; D007150:Immunohistochemistry; D051379:Mice; D008822:Mice, Transgenic; D012165:Retinal Ganglion Cells / Q000502:physiology* / Q000648:ultrastructure*; D014796:Visual Perception / Q000502:physiology*