Effect of beta-bungarotoxin on the release of endogenous amino aids from the sensorimotor cortex.

beta-Bungarotoxin, a snake neurotoxin purified from the venom of Bungarus multicinctus, caused a significant increase in the in vivo release of glutamate from the superfused sensorimotor cortex of awake animals. A smaller effect on GABA release was observed, but no change was detected in the release of six other amino acids measured. The effects on glutamate and GABA release were entirely blocked by tetrodotoxin (1 micrometer) and were reversible when the cortical tissue was washed with saline.