Chemical stimulation of the nucleus tractus solitarii decreases spinal cord blood flow in anesthetized rats

Abstract L -Glutamate was microinjected into the nucleus tractus solitarii (NTS) in anesthetized (chloralose and urethane), paralyzed and artificially ventilated rats, and spinal cord blood flow (SCBF) was determined using a combination of labeled microspheres. Unilateral chemical stimulation of the NTS ( n = 13) significantly decreased SCBF in the cervical cord from 43 ± 6 (mean ± SEM) to 28 ± 4 ( P P − (100 g) − ( P P n = 11). Chemical stimulation of the NTS did not affect the reactivity of the spinal cord vessels to hypercapnia ( n = 5). Microinjection of the vehicle solution into the NTS had no effects on spinal cord circulation ( n = 9). These results suggest that the cell bodies within the NTS may play a role in the control of spinal cord circulation.