Effects of gamma-aminobutyric acid on nerve terminal excitability in a slice preparation of cuneate nucleus.
1 Superfusion of a slice preparation of the rat cuneate nucleus with gamma-aminobutyric acid (GABA) depolarized the afferent nerve fibres and increased their excitability. However, before the depolarization had reached its peak the increased excitability reversed to a decreased excitability, an effect which outlasted the depolarization. 2 Both components of the GABA excitability response were dose-related Cl--dependent and antagonized by bicuculline. 3 Possible mechanisms underlying the sequence of excitability changes are discussed.
D000613:Aminobutyrates / Q000494:pharmacology*; D000818:Animals; D001640:Bicuculline / Q000494:pharmacology; D002712:Chlorides / Q000502:physiology; D004558:Electric Stimulation; D005971:Glutamates / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D008526:Medulla Oblongata / Q000187:drug effects*; D009411:Nerve Endings / Q000187:drug effects*; D009469:Neuromuscular Junction / Q000187:drug effects; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology*
D000613:Aminobutyrates; D002712:Chlorides; D005971:Glutamates; D005680:gamma-Aminobutyric Acid; D011188:Potassium; D001640:Bicuculline