Inhibition by antiepileptics of carbachol but not lithium- or 5-methoxytryptamine-induced wet dog shakes in rats.

The influence of antiepileptic drugs on the wet dog shakes (WDS) induced by intracerebroventricular injections of carbachol (30 micrograms icv) was investigated in rats. Diphenylhydantoin (DPH, 8 and 4 mg/kg), diazepam (0.4, 0.2 and 0.1 mg/kg), phenobarbital (12.5, 6.25 and 3.12 mg/kg), sodium valproate (Depakine, 200, 100 and 50 mg/kg) and trimethadione (200, 100 and 50 mg/kg) given ip inhibited the WDS in a dose-dependent manner. These drugs at the same doses did not change the intensity of shaking behavior induced by lithium chloride or 5-hydroxytryptamine. As the antiepileptic drugs tested in these experiments did not have anticholinergic activity and at used doses were not able to prevent electrical convulsions or pentetrazol-induced seizures, it appears that carbachol-induced WDS could be connected with convulsive activity and could be the initial stage of seizures.