A pyridazinyl derivative of gamma-aminobutyric acid (GABA), SR 95531, is a potent antagonist of Cl- channel opening regulated by GABAA receptors.

ABSTRACT

The antagonistic effects of a pyridazinyl derivative of GABA (SR 95531) were investigated on GABA-induced Cl- currents in neonatal rat cortical neurons in primary culture. Three different methods were used direct application of GABA onto the cell, induction of inhibitory postsynaptic currents (IPSCs) and membrane patch-clamp recordings. Using the first technique, SR 95531 appeared to be more potent than bicuculline methiodide while both drugs seemed equally potent in reducing the IPSC amplitudes and the opening rate of Cl- channels regulated by GABAA receptors in patch-clamp membranes.