Handling-induced seizures and rotational behavior in th Mongolian gerbil

The aim of this report was to examine the relationship between sensory-induced seizures, cerebral laterality (as measured by rotation) and nigrostriatal asymmetry in Mongolian gerbils. Seizure resistant gerbils made proportionally more spontaneous turns to be preferred direction than sensitive animals. Three prototypical antiepileptic drugs strongly elicited rotational behavior (carbamazepine (10-20 mg/kg), diazepam (16 mg/kg) and pentobarbital (40 mg/kg)) and two others (phenobarbital 20-40 mg/kg) and ethosuximide (500 mg/kg)) also appeared to potentiate rotation; only diphenylhydantoin and trimethadione were effective. Two dopaminergic agonists, amphetamine (4 mg/kg) and apomorphine (16 mg/kg) enhanced rotation at anticonvulsant doses while the dopaminergic antagonist haloperidol reduced rotational behavior at a dose (1 mg/kg) which exacerbate seizure severity. Finally, surgical induction of nigrostriatal asymmetry by means of unilateral electrolytic striatal lesions reduced seizure severity; sham and bilateral striatal lesions had no significant effects on seizures. These results suggest that seizure activity and rotational behavior are inversely related and, furthermore, that the link between these two behaviors may be the asymmetry between nigrostriatal dopaminergic systems.