gamma-Aminobutyric acidA (GABAA) receptors modulate [3H]GABA release from isolated neuronal growth cones in the rat.
Potassium-induced release of gamma-[3H]aminobutyric acid [( 3H]GABA) from a growth cone-enriched fraction isolated from neonatal rat forebrain was inhibited by the GABA mimetic muscimol in a dose-dependent manner (IC50 15 nM). The GABA antagonist bicuculline completely reversed the effect of muscimol. Bicuculline alone slightly potentiated the K+-induced release of [3H]GABA. Baclofen, a proposed selective agonist for a bicuculline-insensitive GABAB receptor, was found to cause only a slight reduction in the K+-induced release of [3H]GABA. These results are compatible with the presence of a negative feedback mechanism mediated by GABAA receptors for controlling [3H]GABA release from growth cones of the developing rat forebrain.
Lockerbie
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Gordon-Weeks
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PR
D000818:Animals; D000831:Animals, Newborn / Q000378:metabolism; D001369:Axons / Q000378:metabolism*; D001386:Azides / Q000494:pharmacology; D001418:Baclofen / Q000494:pharmacology; D001549:Benzamides / Q000494:pharmacology; D001640:Bicuculline / Q000031:analogs & derivatives / Q000494:pharmacology; D001921:Brain / Q000378:metabolism; D003712:Dendrites / Q000187:drug effects / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D006706:Homeostasis; D009118:Muscimol / Q000494:pharmacology; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D011963:Receptors, GABA-A / Q000502:physiology*; D013268:Stimulation, Chemical; D013347:Subcellular Fractions / Q000378:metabolism; D014316:Tritium; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D001386:Azides; D001549:Benzamides; D011963:Receptors, GABA-A; D014316:Tritium; D009118:Muscimol; C017069:bicuculline methiodide; D005680:gamma-Aminobutyric Acid; C044896:4-azido-5-iodoclebopride; D001418:Baclofen; D011188:Potassium; D001640:Bicuculline