The influence of spontaneous and visual activity on the development of direction selectivity maps in mouse retina.

Alexandre Tiriac,Miah N Pitcher,Karina Bistrong,Marla B Feller,Joshua M Tworig

doi:10.1016/j.celrep.2021.110225

Alexandre Tiriac, Miah N Pitcher + Show 3 more

Open Access

https://doi.org/10.1016/j.celrep.2021.110225

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Journal: Cell Reports	Publication Date: Jan 1, 2022
Citations: 24	License type: cc-by

Affiliation: University of California, Berkeley

Abstract

SUMMARYIn mice, retinal direction selectivity is organized in a map that aligns to the body and gravitational axes of optic flow, and little is known about how this map develops. We find direction selectivity maps are largely present at eye opening and develop normally in the absence of visual experience. Remarkably, in mice lacking the beta2 subunit of neuronal nicotinic acetylcholine receptors (β2-nAChR-KO), which exhibit drastically reduced cholinergic retinal waves in the first postnatal week, selectivity to horizontal motion is absent while selectivity to vertical motion remains. We tested several possible mechanisms that could explain the loss of horizontal direction selectivity in β2-nAChR-KO mice (wave propagation bias, FRMD7 expression, starburst amacrine cell morphology), but all were found to be intact when compared with WT mice. This work establishes a role for retinal waves in the development of asymmetric circuitry that mediates retinal direction selectivity via an unknown mechanism.

Highlights

Detecting the direction of visual motion, whether generated by self-motion or by objects moving within the visual field, is critical for everyday behavior
Direction-selective retinal ganglion cells (DSGCs) fire more action potentials in response to visual stimuli moving in one direction, called the preferred direction, than visual stimuli moving in the opposite direction, called the null direction (Barlow and Levick, 1965)
To assess whether visual experience influences the establishment of this map, we performed two-photon calcium imaging over large areas of ventronasal and ventrotemporal retinas (Figure 1A)

Summary

Introduction

Detecting the direction of visual motion, whether generated by self-motion or by objects moving within the visual field, is critical for everyday behavior. Not all directions of motion are represented in the visual system. Direction selectivity is first manifested in the retina (Baden et al, 2020). Direction-selective retinal ganglion cells (DSGCs) fire more action potentials in response to visual stimuli moving in one direction, called the preferred direction, than visual stimuli moving in the opposite direction, called the null direction (Barlow and Levick, 1965). In many mammals, including mice, the preferred directions of DSGCs cluster in four groups along two axes. The relative orientations of these axes vary with retinal location––following the axes of optic flow and converging onto points called singularities. Whereas the preferred directions of nasal- and temporal-preferring DSGCs follow the body axis, the preferred directions of dorsal- and ventral-preferring DSGCs follow the gravitational axis (Sabbah et al, 2017)

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