GABA-mediated inhibition in nucleus paragigantocellularis lateralis in the cat.
In decerebrate cats electrical stimulation (10-20 ms trains, 35-450 microA, 0.1 ms pulses, 450 Hz) in nucleus tractus solitarius (NTS, medial or lateral divisions) or nucleus raphe magnus (NRM) inhibited spontaneous or amino acid-induced neuronal activity in nucleus paragigantocellularis lateralis (PGL) for 8-140 (mean 51) ms. Iontophoretically applied GABA (2-50 nA) also inhibited these cells. Iontophoretically applied bicuculline methiodide (10-80 nA) blocked the effects of GABA and reduced the duration of the inhibition evoked from NRM by greater than 50% (5/6 cells) but had no effect on the inhibition evoked from NTS (6/7 cells). The results are discussed in relation to the role of GABA in mediating inhibitory afferent input to PGL.
Lovick
T A
TA
Department of Physiology, Medical School, Birmingham, U.K.
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D001640:Bicuculline / Q000494:pharmacology; D002415:Cats; D003655:Decerebrate State; D004558:Electric Stimulation; D006710:Homocysteine / Q000031:analogs & derivatives / Q000494:pharmacology; D008526:Medulla Oblongata / Q000502:physiology*; D009433:Neural Inhibition / Q000187:drug effects*; D011903:Raphe Nuclei / Q000502:physiology; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology*
D006710:Homocysteine; C007956:homocysteic acid; D005680:gamma-Aminobutyric Acid; D001640:Bicuculline