PROJECT TITLE :

The Retinal Response to Sinusoidal Electrical Stimulation

ABSTRACT:

Rectangular electrical pulses are the first stimulus waveform employed in retinal prosthetics as well as many other neural stimulation applications. Unfortunately, the utility of pulsatile stimuli is limited by the lack to avoid the activation of passing axons, which can lead to the distortion of the spatial patterns of elicited neural activity. Because avoiding axons would possible improve clinical outcomes, the examination of alternate stimulus waveforms is warranted. Here, we tend to studied the response of rabbit retinal ganglion cells (RGCs) to sinusoidal electrical stimulation applied at frequencies of 5, ten, twenty five, and a hundred Hz. Targeted RGCs were restricted to four common varieties: OFF-Brisk Transient, OFF-Sustained, ON-Brisk Transient, and ON-Sustained. Interestingly, response patterns varied between totally different varieties; the foremost notable difference was the comparatively weak response of ON-Sustained cells to low frequencies. Calculation of total spike counts per trial revealed that lower frequencies are a lot of charge economical than high frequencies. Finally, experiments utilizing synaptic blockers revealed that five and 10 Hz activate photoreceptors while twenty five and one hundred Hz activate RGCs. Taken along, our results counsel that while sinusoidal electrical stimulation could provide a useful analysis tool, its clinical utility could be limited.