Recovery of hippocampal cholinergic activity by transplantation of septal neurons in AF64A treated rats.

Embryonic septal neurons were transplanted into the hippocampus of adult rats which had received lateral-ventricular administration of AF64A, a cholinergic neurotoxin, and the effects on hippocampal cholinergic activity were studied. One week after AF64A administration, we injected dissociated septal cell suspension into the dorsal hippocampus, unilaterally. About 3 months after the transplantation, acetylcholine (ACh)-rich septal grafts formed extensive acetylcholinesterase (AChE)-positive fibers into the host hippocampus, recovering choline acetyltransferase (ChAT) level only in the grafted side. These results indicate that septal implants can produce a partial recovery of the cholinergic activity in the chemically damaged hippocampus.