GALANIN MICROINJECTED INTO THE MEDIAL SEPTUM INHIBITS SCOPOLAMINE-INDUCED ACETYLCHOLINE OVERFLOW IN THE RAT VENTRAL HIPPOCAMPUS

Galanin-like immunoreactive terminals hyperinnervate the basal forebra in cholinergic neurons in Alzheimer's disease. To investigate the hypo thesis that galanin acts directly on basal forebrain cell bodies, in v ivo microdialysis studies were conducted in awake rats which analyzed the actions of galanin on acetylcholine release. Microinjection of gal anin into the cholinergic cell body region of the medial septum-diagon al band (MS-DBB) inhibited acetylcholine release in the ventral hippoc ampus. These results are consistent with an interpretation that galani n terminals synapsing on cholinergic cell bodies of the basal forebrai n may serve to inhibit the release of acetylcholine in the terminal fi elds of the cholinergic neurons.