Cerebral extracellular lactate concentration and blood flow during chemical stimulation of the nucleus tractus solitarii in anesthetized rats

Abstract The extracellular lactate concentration and blood flow in the cerebral cortex of urethane-anesthetized, paralyzed and artificially ventilated rats were monitored continuously and simultaneously using an enzyme electrode and a laser Doppler flowmeter (LDF), respectively, during chemical stimulation of the nucleus tractus solitarii (NTS) by microinjection of l -glutamate (1.7 nmol 50 nl). Chemical stimulation of the NTS significantly decreased the arterial blood pressure (ABP) from 85 ± 17 to 68 ± 14 mmHg, heart rate from 418 ± 13 to 402 ± 19 beats · min −1 and cerebral blood flow (CBF) by 17.9 ± 6.2% ( P P