ON and OFF channels in human retinal ganglion cells. (12th November 2012)

• Record Type: Journal Article
• Authors: Hashimoto, Takao; Katai, Satoshi; Saito, Yasunori; Kobayashi, Fumitoshi; Goto, Tetsuya
• Is Part Of: Journal of physiology. Volume 591:Number 1(2013)
• Page Start: 327
• Page End: 337
• Publication Date: 2012-11-12
• Subjects: Physiology -- Periodicals; 612.005
• DOI: 10.1113/jphysiol.2012.243683
• Languages: English
• ISSNs: 0022-3751

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Key points</title> <p> <list id="l1" list-type="simple"> <list-item> <label> </label> <p>The ON and OFF channels are basic functional elements in parallel processing in the visual system in vertebrates including primates, and ON cells excite by positive contrasts, while OFF cells excite by negative contrasts.</p> </list-item> <list-item> <label> </label> <p>We investigated the electrophysiological properties of optic tract fibre activities in neurosurgical patients with Parkinson's disease, focusing on ON‐ and OFF‐type responses to flashlight stimulation.</p> </list-item> <list-item> <label> </label> <p>Most of the multi‐fibre responses at the light on event were excitatory, and excitatory responses at the light off event were observed at a few sites. Analysis of the single‐fiber responses revealed ON fibres and OFF fibres.</p> </list-item> <list-item> <label> </label> <p>All excitatory responses to light on were transient, while all but one excitatory responses to light off were sustained. These different response types are said to contain different modes of visual information.</p> </list-item> <list-item> <label> </label> <p>Our results demonstrate for the first time the ON and OFF channels and their temporal features in visual processing in humans.</p> </list-item> </list> </p> <p> <bold>Abstract </bold> The ON and OFF channels are basic functional elements in parallel processing in the visual system in vertebrates including primates. We analysed the responses of the optic tract fibre activity in response to switching a flashlight on or off in 25 awake patients with Parkinson's disease who underwent stereotactic surgery targeting the internal globus pallidus. The responses were evoked in a darkened room by a light with a luminance of approximately 4 × 10<sup>4</sup> cd m<sup>−2</sup> at the eye and a wide‐spectrum wavelength. Most of the responses at the light on event were excitatory (38 out of 41 sites, 93%). Thirty‐five sites with increase in activity at the light on event showed reciprocal responses or no responses to light off, and these sites were classified as containing ON fibres. In single‐fibre analysis, all of 14 ON fibres were recorded at the sites of multi‐fibre excitatory responses. Six sites showed multi‐fibre excitatory responses at the light off event; three sites showed sustained reduction in activity at the light on event, and these three sites were classified as containing OFF fibres. In single‐fibre analysis, two OFF fibres were recorded at the sites of multi‐fibre suppressive responses at the light on event, and the other two OFF fibres were recorded at the sites of multi‐fibre excitatory responses at the light on event. We found that all excitatory responses to light on were transient, while all but one excitatory responses to light off were sustained. Reduction in activity tended to be smaller than increase in activity at the light on event. These results demonstrate that the ON and OFF channels, and their transient and sustained features function in visual processing in humans.</p> </abstract>