γ-Aminobutyric Acid-Activated 36Cl- Influx: A Functional In Vitro Assay for CNS γ-Aminobutyric Acid Receptors of Insects |
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| Authors: | K A Wafford D B Sattelle I Abalis A T Eldefrawi M E Eldefrawi |
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| Institution: | AFRC Unit of Insect Neurophysiology and Pharmacology, Department of Zoology, University of Cambridge, Cambridge, England;Department of Pharmacology and Experimental Therapeutics, University of Maryland School of Medicine, Baltimore, Maryland, U.S.A. |
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| Abstract: | The effects of gamma-aminobutyric acid (GABA) on the uptake of 36Cl- into a membrane microsac preparation from isolated nerve cords of the cockroach Periplaneta americana was studied. On addition of 1 microM GABA (after 4-s incubation, then rapid quenching) the influx of 36Cl- was stimulated to a level 75% above that of the control value. This stimulation was reduced by picrotoxin (100 microM), but was not significantly affected by bicuculline (100 microM). Results of 36Cl- influx experiments are in agreement with data obtained from radiolabelled ligand binding assays and electrophysiological investigations on the same tissue. The method described represents a functional in vitro assay for CNS GABA receptors of insects. |
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| Keywords: | γ-Aminobutyric acid 36Cl- influx Picrotoxin Bicuculline |
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