Radial maze learning deficits and mediodorsal thalamic damage in context of multifocal seizure-induced brain lesions.

Abstract

Rats were either trained 21 days after seizure induction or trained before seizure induction and tested 21 days later. The seizures, which induce insidious brain damage within a multitude of diencephalic and subcortical telencephalic structures, were induced by a single injection of lithium (3 mEq/kg sc) followed 24 hr later by pilocarpine (30 mg/kg sc). Compared with controls, the treated rats displayed significant deficits in the acquisition and recall of a radial maze task. Although there was multifocal brain damage, only the amount of damage within the mediodorsal thalamic group was significantly and strongly correlated (rho = .79) with numbers of errors.