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Title: Cat retinal ganglion cell receptive-field alterations after 6-hydroxydopamine induced dopaminergic amacrine cell lesions

Optic tract single-unit recordings were used to study ganglion cell response functions of the intact cat eye after 6-hydroxydopamine (6-OHDA) lesioning of the dopaminergic amacrine cell (AC) population of the inner retina. The impairment of the dopaminergic AC was verified by high pressure-liquid chromatography with electrochemical detection of endogenous dopamine content and by (/sup 3/H)dopamine high-affinity uptake; the dopaminergic ACs of the treated eyes demonstrated reduced endogenous dopamine content and reduced (/sup 3/H)dopamine uptake compared with that of their matched controls. Normal appearing (/sup 3/H)GABA and (/sup 3/H)-glycine uptake in the treated retinas suggests the absence of any nonspecific action of the 6-OHDA on the neural retina. The impairment of the dopaminergic AC population was found to alter a number of response properties in off-center ganglion cells, but this impairment had only a modest effect on the on-center cells. An abnormally high proportion of the off-center ganglion cells in the 6-OHDA treated eyes possessed nonlinear, Y-type receptive fields. These cells also possessed shift-responses of greater than normal amplitude, altered intensity-response functions, reduced maintained activities, and more transient center responses. Of the on-center type cells, only the Y-type on-center cells were affected by 6-OHDA, possessing higher than normal maintained activities andmore » altered intensity-response functions. The on-center X-cells were unaffected by 6-OHDA treatment. The dopaminergic AC of the photopically adapted cat retina therefore modulates a number of ganglion cell response properties and within the limits of this study is most prominent in off-center ganglion cell circuitry.« less
Authors:
;
Publication Date:
OSTI Identifier:
5241837
Resource Type:
Journal Article
Resource Relation:
Journal Name: J. Neurophysiol.; (United States); Journal Volume: 6
Research Org:
Univ. of Miami School of Medicine, FL
Country of Publication:
United States
Language:
English
Subject:
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.; 59 BASIC BIOLOGICAL SCIENCES; DOPAMINE; BIOLOGICAL EFFECTS; RETINA; INJURIES; AFFINITY; CATS; GANGLIONS; GLYCINE; LIQUID COLUMN CHROMATOGRAPHY; NEUROREGULATORS; TRACER TECHNIQUES; TRITIUM COMPOUNDS; UPTAKE; AMINES; AMINO ACIDS; ANIMALS; AROMATICS; AUTONOMIC NERVOUS SYSTEM AGENTS; BODY; BODY AREAS; CARBOXYLIC ACIDS; CARDIOTONICS; CARDIOVASCULAR AGENTS; CHROMATOGRAPHY; DRUGS; EYES; FACE; HEAD; HYDROXY COMPOUNDS; ISOTOPE APPLICATIONS; LABELLED COMPOUNDS; MAMMALS; NERVOUS SYSTEM; ORGANIC ACIDS; ORGANIC COMPOUNDS; ORGANS; PHENOLS; POLYPHENOLS; SENSE ORGANS; SEPARATION PROCESSES; SYMPATHOMIMETICS; VERTEBRATES 560305* -- Chemicals Metabolism & Toxicology-- Vertebrates-- (-1987); 550201 -- Biochemistry-- Tracer Techniques