EFFECT OF STIMULATION OF THE NUCLEUS BASALIS OF MEYNERT ON BLOOD-FLOW AND EXTRACELLULAR LACTATE IN THE CEREBRAL-CORTEX WITH SPECIAL REFERENCE TO THE EFFECT OF NOXIOUS-STIMULATION OF SKIN AND HYPOXIA

Cerebral blood flow (CBF) and extracellular lactate in the parietal cortex were simultaneously measured in halothane-anesthetized rats. Focal electrical stimulation of the magnocellular nucleus of the basal forebrain (nucleus basalis of Meynert; NBM) for 10 min produced a significant increase in cortical CBF without any significant changes in extracellular lactate in the parietal cortex or in systemic arterial blood pressure (BP). Cutaneous pinching of a hindpaw for 10 min increased cortical CBF and BP, but did not influence extracellular cortical lactate. Systemic hypoxia for 10 min reducing the end-tidal O2 concentration from 18% to 6-8% produced a remarkable increase in extracellular cortical lactate. It was suggested that the increased cortical CBF following either NBM stimulation or pinching of a hindpaw was not due to metabolic changes in the cortical neurons of anesthetized rats. © 1990.