The effect of GABA on neurotransmission in frog tectal slices.
The regional distribution of gamma-aminobutyric acid (GABA) was determined in the central nervous system of the frog. The highest amount of GABA was found in the tectum (35.7 +/- 2.3 mmol/kg protein). A thin tectal slice (400-600 microns thick) preparation was developed in which the postsynaptic potential (PSP) could be elicited. The addition of GABA to the perfusion medium depressed the PSP in a dose-dependent manner in the concentration range 1-12.5 mM at 28 degrees C. Nipecotic acid, a GABA uptake inhibitor, at a concentration of 0.5 mM shifted the dose-response curve for GABA to the left. These results from the frog, a cold-blooded animal, were in good agreement with those for hippocampal slices from the guinea-pig.
Arakawa
T
T
Department of Physiology, Kobe University School of Medicine, Japan.
Okada
Y
Y
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D004558:Electric Stimulation; D066298:In Vitro Techniques; D009557:Nipecotic Acids / Q000494:pharmacology; D011392:Proline / Q000031:analogs & derivatives*; D011892:Rana catesbeiana / Q000502:physiology*; D013477:Superior Colliculi / Q000187:drug effects / Q000502:physiology*; D009435:Synaptic Transmission / Q000187:drug effects*; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology*
D009557:Nipecotic Acids; C030278:nipecotic acid; D005680:gamma-Aminobutyric Acid; D011392:Proline; C010983:homoproline