High-resolution VSDI retinotopic mapping via a DLP-based projection system.

Adi Gross,Yossi Mandel,Nadav H Ivzan,Nairouz Farah

doi:10.1364/boe.10.005117

Abstract

High-resolution recording of visual cortex activity is an important tool for vision research. Using a customized digital mirror device (DMD) - based system equipped with retinal imaging, we projected visual stimuli directly on the rat retina and recorded cortical responses by voltage-sensitive dye imaging. We obtained robust cortical responses and generated high-resolution retinotopic maps at an unprecedented retinal resolution of 4.6 degrees in the field of view, while further distinguishing between normal and pathological retinal areas. This system is a useful tool for studying the cortical response to localized retinal stimulation and may shed light on various cortical plasticity processes.

Highlights

Recording the population response of the visual cortex is of great importance for studying basic visual processing, plasticity processes, and various pathologies
To overcome the limitations of the available systems, we developed a unique projection system based on a slit lamp equipped with a Digital Micromirror Device - Digital Light Processing (DMD-DLP), which enables an accurate projection of patterns on a desired region
An increase in stimulus irradiance was accompanied with only a small decrease in the response latency (Fig. 2(C)) and a slower decay, compared with the rising phase, probably because it reflects a population response [29], where neurons farther away from the center of activity are activated later, slowing down the decay phase

Summary

Introduction

Recording the population response of the visual cortex is of great importance for studying basic visual processing, plasticity processes, and various pathologies. The dye molecules convert changes in the membrane potential into changes in the emitted fluorescence [6,7], which is detected by an optical system This technique enables the high-spatial and temporal resolution imaging of the cortex in general [8,9] and is widely used for studying the visual cortex in primates [10,11,12,13], cats [14,15], and rodents [3,16]. Third delivering high powered light for optogenetic stimulation [19] or for retinal prostheses stimulation [20,21] is challenging These approaches rely on the optical system of the rodent, which is known to introduce a large amount of aberration to the image [22,23], degrading the visual function and electrophysiological responses [24].

Methods

Results

Conclusion