|
|
||||||||
1Departments of Vision Science and 2Bioengineering and Molecular and 3Cell Biology, University of California, Berkeley, California
Submitted 11 August 2005; accepted in final form 12 October 2005
The goal of retinal prosthetic devices is to generate meaningful visual information in patients that have lost outer retinal function. To accomplish this, these devices should generate patterns of ganglion cell activity that closely resemble the spatial and temporal components of those patterns that are normally elicited by light. Here, we developed a stimulus paradigm that generates precise temporal patterns of activity in retinal ganglion cells, including those patterns normally generated by light. Electrical stimulus pulses (
1-ms duration) elicited activity in neurons distal to the ganglion cells; this resulted in ganglion cell spiking that could last as long as 100 ms. However, short pulses, <0.15 ms, elicited only a single spike within 0.7 ms of the leading edge of the pulse. Trains of these short pulses elicited one spike per pulse at frequencies
250 Hz. Patterns of short electrical pulses (derived from normal light elicited spike patterns) were delivered to ganglion cells and generated spike patterns that replicated the normal light patterns. Finally, we found that one spike per pulse was elicited over almost a 2.5:1 range of stimulus amplitudes. Thus a common stimulus amplitude could accommodate a 2.5:1 range of activation thresholds, e.g., caused by differences arising from cell biophysical properties or from variations in electrode-to-cell distance arising when a multielectrode array is placed on the retina. This stimulus paradigm can generate the temporal resolution required for a prosthetic device.
This article has been cited by other articles:
![]() |
D. J. Margolis, G. Newkirk, T. Euler, and P. B. Detwiler Functional Stability of Retinal Ganglion Cells after Degeneration-Induced Changes in Synaptic Input J. Neurosci., June 18, 2008; 28(25): 6526 - 6536. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Sekirnjak, P. Hottowy, A. Sher, W. Dabrowski, A. M. Litke, and E. J. Chichilnisky High-Resolution Electrical Stimulation of Primate Retina for Epiretinal Implant Design J. Neurosci., April 23, 2008; 28(17): 4446 - 4456. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. J. DeMarco Jr, G. L. Yarbrough, C. W. Yee, G. Y. McLean, B. T. Sagdullaev, S. L. Ball, and M. A. McCall Stimulation via a Subretinally Placed Prosthetic Elicits Central Activity and Induces a Trophic Effect on Visual Responses Invest. Ophthalmol. Vis. Sci., February 1, 2007; 48(2): 916 - 926. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |