SPATIO–TEMPORAL RECEPTIVE FIELDS AND TRANSFER FUNCTIONS OF HUMAN GANGLION CELL POPULATIONS

Abstract

Abstract: : Purpose: To study spatio–temporal receptive fields and encoding of luminance information in populations of human retinal ganglion cells. Methods: Eyes were obtained from organ transplant donors and patches of isolated retina were placed in a recording setup and superfused with Ames medium. The responses to different patterns of visual stimuli were recorded from many ganglion cells simultaneously using an array of 100 microelectrodes. Responses were recorded with a 100 channel data acquisition system and stored on a Pentium–based computer for later analysis. Models of stimulus encoding were generated in order to get as much information as possible about the linear and nonlinear elements of the neural code. Results: Multielectrode arrays provide a useful means to record simultaneously from many retinal ganglion cells in human retina ensuring stable electrode/neuron apposition. In each experiment we recorded neural activity from about 30–50 lectrodes. From 8 human eyes we got 583 classifiable units. From these responses the spatio–temporal receptive fields (STRF) and transfer functions (TF) were calculated. We found that population responses can be decomposed and described based on filter and coding features of individual cells. Conclusions: It is possible to make single and multi–unit recordings of human retinal ganglion cells using multielectrode arrays. The determination of the filter features of populations of retinal ganglion cells studied using simultaneous recording techniques provides information about possible visual encoding strategies for machine–brain interfaces and neural prostheses.

Keywords: electrophysiology: non–clinical • retina: proximal (bipolar, amacrine, and ganglion cells) • retina: neurochemistry