Effects of physostigmine on AF64A-induced impairment of learning acquisition in rats.

Ethylcholine aziridinium ion (AF64A), a putative cholinotoxin, was administered into the cerebroventricles of rats, and the effects on learning behaviors were observed. AF64A caused the impairment of learning acquisition in both passive and active avoidance responses. Physostigmine, a cholinesterase inhibitor, antagonized these changes at the doses of 0.03 to 0.1 mg/kg. Our behavioral study may indicate that the central cholinergic system might play a role in AF64A-induced impairment.