Behavioural and electroencephalographic effects of Tityus serrulatus scorpion venom in rats.

This study was designed to investigate the convulsant effects of T. serrulatus scorpion venom in rats. Pretreatment of rats with venom increased the minimum convulsant dose of picrotoxin, impaired convulsion generalization and displaced to the left the dose-response curve for picrotoxin. It also decreased the intensity but prolonged the duration of seizures caused by pentylenetetrazol injection. Microinjection of the venom into the dorsal hippocampus induced behavioural alterations and epileptiform waves in the EEG. Venom also altered the threshold for, and intensity of, convulsions induced in different experimental models of epilepsy. Different fractions of the venom may be responsible for these different effects. Therefore, purification of venom toxins is necessary for the complete understanding of the present results.