Stimulation of the nucleus basalis of Meynert increases cerebral cortical blood flow in rats

Focal electrical stimulation of the magnocellular nucleus of the basal forebrain (nucleus basalis of Meynert; NBM) or a microinjection of l-glutamate (50 nmol) into the NBM increased cerebral cortical blood flow in the parietal lobe in urethane-anesthetized rats. The vasodilative responses were elicited only ipsilateral to the site of stimulation. Most of the vasodilative responses were abolished by intravenous administrations of muscarinic and nicotinic cholinergic blocking agents (atropine 0.5 mg/kg and mecamylamine 2 mg/kg). This suggests that the cholinergic projecting system sending fibers from the NBM to the parietal lobe contributes to the vasodilation of the cortex by activating muscarinic and nicotinic cholinergic receptors.