Immunolesion of the cholinergic basal forebrain :effects on functional properties of hippocampal and septalneurons

Abstract Deficits in cholinergic function have been documented in a variety of brain disordersincluding Alzheimers Disease and, to a lesser extent, in normal ageing. In the present article, wehave reviewed our recent findings on the effects of the loss of basal forebrain cholinergic neuronson the functional properties of the septohippocampal pathway. In vivo and ex vivo investigations were performed in rats following basal forebrain cholinergic lesion with thespecific immunotoxin 192 IgG-saporin. Our results suggest a significant contribution ofcholinergic neurons in the rhythmically bursting activity recorded within the medial septum. Inaddition, they give evidence that acetylcholine may tonically decrease the glutamatergic synapticresponses in the hippocampus whereas the GABAergic mediated inhibitory potentials are notaffected. The possible contribution of these cholinergic mechanisms in the age-related functionalalterations of the septohippocampal activity is discussed.