| Functional inhibition in direction-selective retinal ganglion cells: spatiotemporal extent and intralaminar interactions. | |
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MedLine Citation:
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PMID: 12163551 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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We recorded from ON-OFF direction-selective ganglion cells (DS cells) in the rabbit retina to investigate in detail the inhibition that contributes to direction selectivity in these cells. Using paired stimuli moving sequentially across the cells' receptive fields in the preferred direction, we directly confirmed the prediction of that a wave of inhibition accompanies any moving excitatory stimulus on its null side, at a fixed spatial offset. Varying the interstimulus distance, stimulus size, luminance, and speed yielded a spatiotemporal map of the strength of inhibition within this region. This "null" inhibition was maximal at an intermediate distance behind a moving stimulus: 1/2 to 11/2 times the width of the receptive field. The strength of inhibition depended more on the distance behind the stimulus than on stimulus speed, and the inhibition often lasted 1-2 s. These spatial and temporal parameters appear to account for the known spatial frequency and velocity tuning of ON-OFF DS cells to drifting contrast gratings. Stimuli that elicit distinct ON and OFF responses to leading and trailing edges revealed that an excitatory response of either polarity could inhibit a subsequent response of either polarity. For example, an OFF response inhibited either an ON or OFF response of a subsequent stimulus. This inhibition apparently is conferred by a neural element or network spanning the ON and OFF sublayers of the inner plexiform layer, such as a multistratified amacrine cell. Trials using a stationary flashing spot as a probe demonstrated that the total amount of inhibition conferred on the DS cell was equivalent for stimuli moving in either the null or preferred direction. Apparently the cell does not act as a classic "integrate and fire" neuron, summing all inputs at the soma. Rather, computation of stimulus direction likely involves interactions between excitatory and inhibitory inputs in local regions of the dendrites. |
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Authors:
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Steven F Stasheff; Richard H Masland |
Publication Detail:
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Type: Journal Article; Research Support, U.S. Gov't, P.H.S. |
Journal Detail:
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Title: Journal of neurophysiology Volume: 88 ISSN: 0022-3077 ISO Abbreviation: J. Neurophysiol. Publication Date: 2002 Aug |
Date Detail:
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Created Date: 2002-08-06 Completed Date: 2002-09-23 Revised Date: 2007-11-14 |
Medline Journal Info:
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Nlm Unique ID: 0375404 Medline TA: J Neurophysiol Country: United States |
Other Details:
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Languages: eng Pagination: 1026-39 Citation Subset: IM |
Affiliation:
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Department of Neurology, Children's Hospital, Harvard Medical School, Boston 02115, USA. sfs@massmed.org |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Action Potentials Animals Electrophysiology Female Fluorescent Dyes Isoquinolines Male Neural Inhibition / physiology* Rabbits Retinal Ganglion Cells / physiology* Visual Perception / physiology |
| Grant Support | |
ID/Acronym/Agency:
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NS-01701-09/NS/NINDS NIH HHS |
| Chemical | |
Reg. No./Substance:
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0/Fluorescent Dyes; 0/Isoquinolines; 77944-88-8/lucifer yellow |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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