MEDULLARY CARDIOVASCULAR CENTER AND ACUTE BRAIN-SWELLING

Acute brain swelling is reported to be due to acute vasodilatation of cerebral vessels. One of the causes of acute brain swelling may be dis turbance of central control mechanisms of cerebral vessels. It has bee n reported that the anatomical location of the area which controls cer ebral circulation is related to the area which controls systemic circu lation. However, the role of the cardiovascular center on cerebral cir culation has not been clear. The present study was, therefore, underta ken to examine the effects of chemical stimulation of the medullary ca rdiovascular center [nucleus tractus solitarius (NTS), ventrolateral d epressor area (VLDA), and ventrolateral pressor area (VLPA)] on cerebr al circulation. In anesthetized, paralyzed and artificially ventilated rats, the neurons in the NTS, VLDA, and VLPA were chemically stimulat ed and the cerebral blood flow (CBF) was determined using labeled micr ospheres. The CBF decreased significantly and the cerebrovascular resi stance (CVR) increased significantly by chemical stimulation of the NT S, VLDA, and VLPA. These results suggest that the neurons within the N TS, VLDA, and VLPA control cerebral vessels vasoconstrictively. There is a possibility that the dysfunction of the NTS, VLDA, and VLPA may c ause acute brain swelling.