The Anticonvulsant and Thermal Effects of Various Cannabinoids in Rats

Abstract

While the neurophysiological basis of the epileptic syndrome seems to be clear, its neurochemical basis is still unknown. Among the proposed medical uses for various cannabinoids is its use as an anticonvulsant agent. Various cannabinoids exert some anticonvulsant effects in animal models of experimental epilepsy.

In this study the anticonvulsant effects of three cannabinoids (delta-6-THC; delta-6-THC-DMH; and SP-175) were tested in PTZ-treated rats. It has been shown before that doses of d-amphetamine caused an augmentation of PTZ effect, i.e., a decrease in reaction time, an increase in the severity of the attack, and an increase in death rate. The thermal effect of these cannabinoids was also tested in d-amphetamine-treated rats kept at 4°C. d-Amphetamine itself induced hypothermia among rats kept at 4°C, and this effect of d-amphetamine is due to its ability to release dopamine in the DA mesolimbic pathway.

Only SP-175 had a protective effect against seizures produced by either PTZ alone or by d-amphetamine and PTZ; delta-6-THC and delta-6-THC-DMH did not have this effect. On the other hand, only delta-6-THC produced hypothermia and caused an increase in the d-amphetamine hypothermia among rats kept at 4°C. Our conclusion is that SP-175 has an anticonvulsant effect in our model, and this effect is not due to any interaction of the drug with the DA system.