ELECTROPHYSIOLOGICAL RESPONSES OF ISOLATED LOCUST (SCHISTOCERCA-GREGARIA) SOMATA TO TAURINE AND GABA APPLICATION

The comparative effects of applied taurine and GABA on isolated locust neural somata has been studied. Iontophoretically applied taurine and GABA both hyperpolarized and decreased membrane resistance in the pre paration. GABA was markedly the more potent of the two amino acids in this respect. Both amino acids showed similar reversal potentials (aro und -75 mV) when tested on somata held at a series of membrane potenti als. The actions of both amino acids were antagonized by picrotoxin an d the proposed specific taurine antagonist thyl-3-methyl-4H-1,2,4-benz thiadiazine-1,l-dioxide hydrochloride. Responses to both amino acids w ere augmented by the benzodiazepine flunitrazepam. The data suggest th at taurine and GABA act at a common site in locust somata.