gms | German Medical Science

Artificial Vision 2017

The International Symposium on Visual Prosthetics

01.12. - 02.12.2017, Aachen

Temporal patterns of single-unit responses from on- and off-cells in the lateral geniculate nucleus elicited by suprachoroidal-transretinal stimulation

Meeting Abstract

  • Hiroyuki Kanda - Dept. of Applied Visual Science, Graduate School of Medicine, Osaka University, Suita, Japan
  • T. Miyoshi - Dept. Of Integrative Physiology, Graduate School of Medicine, Osaka University, Suita, Japan
  • T. Morimoto - Dept. of Applied Visual Science, Graduate School of Medicine, Osaka University, Suita, Japan
  • T. Fujikado - Dept. of Applied Visual Science, Graduate School of Medicine, Osaka University, Suita, Japan

Artificial Vision 2017. Aachen, 01.-02.12.2017. Düsseldorf: German Medical Science GMS Publishing House; 2017. Doc17artvis20

doi: 10.3205/17artvis20, urn:nbn:de:0183-17artvis204

Published: November 30, 2017

© 2017 Kanda et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 License. See license information at http://creativecommons.org/licenses/by/4.0/.


Outline

Text

Objective: To investigate differences in the pattern of neural responses from on- and off-cells to suprachoroidal-transretinal stimulation (STS), we recorded single-unit responses from relay cells in the lateral geniculate nucleus (LGN).

Methods: Under general anesthesia, a recording electrode was inserted into the LGN of cats (n = 5), and 18 single-units (9 on-center and 9 off-center) were recorded. Receptive fields and cell types were identified by light stimulation. For suprachoroidal stimulation, a multiple electrode array comprised of bullet-shaped platinum electrodes (diameter = 0.5 mm and height = 0.3 mm each) were used. The array was inserted into the scleral pocket at the posterior pole of the eye. Single biphasic pulses of 0.5 ms/phase were applied to the retina. Spike discharges evoked by STS at a variety of current intensities were recorded in each unit. The patterns of spike discharges were analyzed using a post-stimulus time histogram.

Results: In both on- and off-cells, repetitive bursts were obtained in response to STS. Within 10 ms after the stimulus onset, spike discharges were observed in both on- and off-units. Between 10 and 60 ms after the stimulus onset, the on-and off-units discharged alternately.

Discussion: Crapper and Noell have reported that repetitive bursts occurred in retinal ganglion cells in response to transretinal electrical stimulation in rabbits (JNP, 1965). Therefore, the characteristic patterns of responses in on- and off-cells were probably derived from the activation of retinal circuits. The results might contribute to develop optimal stimulation methods that selectively activate different cell types.