Open Accessgamma-Aminobutyric acid: a neurotransmitter candidate for cone horizontal cells of the catfish retina.
Author(s) -
Dominic Man Kit Lam,
Eric M. Lasater,
Kén-Ichi Naka
Publication year - 1978
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.75.12.6310
Subject(s) - retina , bicuculline , neurotransmitter , catfish , postsynaptic potential , gamma aminobutyric acid , biophysics , neuroscience , biology , gaba receptor antagonist , anatomy , microbiology and biotechnology , receptor , gabaa receptor , biochemistry , central nervous system , fish <actinopterygii> , fishery
In the catfish retina, horizontal cells that receive inputs exclusively from red-sensitive cones are the only neurons that accumulate exogenous gamma-aminobutyric acid under our experimental conditions. When isolated eyecups are perfused with bicuculline methochloride, an antagonist of postsynaptic gamma-aminobutyric acid receptors, responses of cone photoreceptors to a field of light (3 mm in diameter) become much slower and approach those to a small spot of light (0.3 mm). In addition, bicuculline methochloride decreases the frequency responses of cone horizontal cells to a field of light. These findings indicate that, in the catfish retina, feedback synapses from cone horizontal cells to cones are chemically mediated and may use gamma-aminobutyric acid as a neurotransmitter. Our results also confirm the hypothesis that, in the catfish retina, a function of the negative feedback is to improve the frequency responses of the system.