Verapamil-induced behavioral, autonomic and motor effects in cats.

The effects of verapamil, a calcium antagonist, injected into the cerebral ventricles on behavior, autonomic and motor activity of unanesthetized cats have been investigated. Verapamil evoked emotional behavior (miaowing and alertness), autonomic responses (mydriasis, tachypnoea, dyspnoea, defecation, micturition, licking and panting) and motor phenomena (ataxia, muscular weakness and adynamia). These effects lasted from a few minutes to several hours. The most consistent phenomena were miaowing, alertness, mydriasis and respiratory irregularities. The possible mechanism of action of verapamil on behavior, autonomic and motor activity may be an action on voltage-operated calcium channels in the brain.