Effects of tityustoxin (TsTX) from scorpion venom on the release and synthesis of acetylcholine in brain slices.

Tityustoxin (TsTX) increased the release and synthesis of acetylcholine (ACh) in slices of rat brain hippocampus, hypothalamus, thalamus, cortex and striatum. The effect was highest in slices of hippocampus and cortex and smallest in hypothalamus. These effects of TsTX were dependent on the presence of Na+ and Ca2+ in the incubation medium. EGTA, 0.1 mM, blocked the effect of TsTX in all areas, except for the hippocampus and frontal striatum, where a concentration of 10 mM was required. Tetrodotoxin blocked the increase in the release and synthesis of ACh induced by tityustoxin.