Effects of intrahippocampal injections of the cholinergic neurotoxin AF64A on open-field activity and avoidance learning in the rat.
The effects of direct intrahippocampal administration of the cholinergic neurotoxin, AF64A, were investigated in male rats. Bilateral injections of AF64A (5 nmole/2 microliters) produced a significant decrease in choline acetyltransferase (CAT) activity in the dorsal hippocampus (25%) and overlying frontoparietal cortex (30%) but no changes in the striatum. Rats lesioned with AF64A exhibited increased levels of open-field activity, which was most marked at 1 week after the lesion; however, the rates of intrasession habituation were similar in lesioned and control rats. Lesioned rats also displayed deficits in acquisition and retention of a passive avoidance task and less dramatic deficits in acquisition of two-way shuttle box avoidance. These findings indicate that lesioning of cholinergic terminals in the hippocampus and/or cerebral cortex with AF64A leads to long-term deficits in learning and memory as well as increases in open-field activity.
D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects*; D001388:Aziridines / Q000494:pharmacology*; D001389:Azirines / Q000494:pharmacology*; D002540:Cerebral Cortex / Q000201:enzymology; D002794:Choline / Q000031:analogs & derivatives* / Q000494:pharmacology; D002795:Choline O-Acetyltransferase / Q000378:metabolism; D002799:Cholinergic Fibers / Q000187:drug effects; D003342:Corpus Striatum / Q000201:enzymology; D006624:Hippocampus / Q000187:drug effects* / Q000201:enzymology; D008297:Male; D008568:Memory / Q000187:drug effects; D009043:Motor Activity / Q000187:drug effects*; D051381:Rats; D011919:Rats, Inbred Strains
D001388:Aziridines; D001389:Azirines; C044894:ethylcholine aziridinium; D002795:Choline O-Acetyltransferase; D002794:Choline