Electrical multisite stimulation of the isolated chicken retina

Visual prostheses such as subretinal implants are intended for electrical m ultisite excitation of the retinal network. To investigate relevant issues like spatial resolution and operational range, we have developed an in vitr o method using microelectrode arrays to stimulate isolated retinae. Ganglio n cell activity in the chicken retina evoked by distally applied spatial vo ltage patterns consisted of fast bursts, transient inhibition and delayed d ischarges, and depended on the amount, location and spatial pattern of the injected charge. The response was altered or disappeared when synaptic tran smission was blocked. Our results indicate that shape perception and object location can be partially achieved with subretinal electrical multisite st imulation. (C) 2000 Elsevier Science Ltd. All rights reserved.