A receptor with GABAC-like pharmacology in invertebrate neurones in culture.
We have characterized in crustacean neurones in culture a receptor for gamma-aminobutyric acid (GABA) which conforms to the pharmacological profile of the proposed type-C GABA receptor (GABAC) found in the vertebrate retina. It is associated with a chloride-selective ion channel and is blocked by picrotoxin. It is neither inhibited by bicuculline nor activated by baclofen, while diazepam and phenobarbital are without modulatory effect. Like the GABAC-like receptor of the vertebrate retina it is activated by the folded GABA analogue cis-4-aminocrotonic acid (CACA). Desensitization is moderate allowing for a more sustained action of GABA. Single channel recordings revealed a bicuculline-resistant GABA- and CACA-activated chloride channel with a conductance about eight times higher than that described for the bicuculline-resistant GABA receptor channel from the rat retina.
Jackel
C
C
Laboratoire de Neurobiologie et Physiologie Comparées, Université de Bordeaux I, Arcachon, France.
Krenz
W D
WD
Nagy
F
F
D000818:Animals; D001640:Bicuculline / Q000494:pharmacology; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D002478:Cells, Cultured; D018118:Chloride Channels / Q000187:drug effects / Q000378:metabolism; D003437:Crotonates / Q000494:pharmacology; D017952:Ganglia, Invertebrate / Q000187:drug effects / Q000378:metabolism; D007700:Kinetics; D008121:Nephropidae; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D018079:Receptors, GABA / Q000187:drug effects*; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology
D018118:Chloride Channels; D003437:Crotonates; D018079:Receptors, GABA; C055331:4-aminocrotonic acid; D005680:gamma-Aminobutyric Acid; D001640:Bicuculline