Purchase this article with an account.
R.J. Jensen, J.F. Rizzo; Responses of Rabbit Retinal Ganglion Cells to Electrical Stimulation With a Subretinal Electrode . Invest. Ophthalmol. Vis. Sci. 2005;46(13):5279.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose: Previously, we reported on the responses of rabbit retinal ganglion cells (RGCs) to electrical stimulation with a 500 µm diameter epiretinal electrode. We now report on the responses of RGCs with the same electrode, placed subretinally. Methods: Extracellular recordings were made from RGCs in an isolated rabbit retinal preparation. RGCs were stimulated electrically with monophasic current pulses (0.1 to 50 msec duration) through a 500 µm diameter electrode which was positioned on the outer retinal surface within the optical receptive field. Results: Data were obtained from 19 Off–center and 18 On–center RGCs. All RGCs elicited a burst of action potentials upon electrical stimulation of the retina. Threshold current for activation of RGCs decreased with increased pulse duration. For Off–center RGCs, the median threshold current (MTC) for anodal current pulses was 5 to 7.5 times lower (for most pulse durations) than the MTC for cathodal current pulses. For 2–msec pulses, the MTC for anodal and cathodal current pulses were 0.88 µA and 5.6 µA, respectively. For On–center RGCs, the MTCs for anodal and cathodal current pulses were similar for all pulse durations. For 2–msec pulses, the MTC for anodal and cathodal current pulses were 1.8 µA and 1.3 µA, respectively. The latency of the responses depended upon the polarity of the stimulus. For short–duration current pulses, the latencies were typically 4–16 msec for anodal stimulation of Off–center RGCs and cathodal stimulation of On–center RGCs. The latencies were more widely distributed for cathodal stimulation of Off–center RGCs and anodal stimulation of On–center RGCs, ranging from 3 to 60 msec. Conclusions: The threshold currents are as low as, if not lower than, those found in previous experiments, using the same electrode to stimulate the retina on the epiretinal surface. Our findings also indicate that for a subretinal prosthesis, cathodal current pulses may selectively activate On–center RGCs, whereas anodal current pulses tend to favor activation of Off–center RGCs.
This PDF is available to Subscribers Only