Campos R R, McAllen R M
Howard Florey Institute of Experimental Physiology and Medicine, University of Melbourne, Parkville 3052, Australia.
Am J Physiol. 1999 Apr;276(4):R1209-13. doi: 10.1152/ajpregu.1999.276.4.R1209.
The responses of sympathetic premotor neurons in the rostral ventrolateral medulla (RVLM) to activation or inactivation of neurons in the caudal pressor area (CPA) were studied in urethan-anesthetized rats. Extracellular recordings were made from 32 barosensitive single units in the RVLM, of which 26 were antidromically activated from the cervical cord. Unilateral microinjections of L-glutamate (0.5-5 nmol) into the CPA increased firing in 13 of 14 premotor neurons by 90 +/- 30% while raising blood pressure. Both ipsilateral and contralateral injections were effective. Unilateral or bilateral inhibition of CPA neuron activity by microinjecting glycine (5-200 nmol/side) lowered blood pressure, while it reduced firing in 9 of 10 and 16 of 17 premotor neurons, respectively, by 45 +/- 9 and 39 +/- 6%. A significant proportion of tonic activity in RVLM sympathetic premotor neurons is thus driven, directly or indirectly, by neurons in the CPA.
在乌拉坦麻醉的大鼠中，研究了延髓头端腹外侧区（RVLM）交感节前运动神经元对尾侧升压区（CPA）神经元激活或失活的反应。从RVLM中的32个压力敏感单神经元进行细胞外记录，其中26个通过颈髓进行逆向激活。向CPA单侧微量注射L-谷氨酸（0.5-5 nmol）可使14个节前运动神经元中的13个放电增加90±30%，同时血压升高。同侧和对侧注射均有效。通过微量注射甘氨酸（5-200 nmol/侧）单侧或双侧抑制CPA神经元活动可降低血压，同时分别使10个节前运动神经元中的9个和17个节前运动神经元中的16个放电减少45±9%和39±6%。因此，RVLM交感节前运动神经元的很大一部分紧张性活动是由CPA中的神经元直接或间接驱动的。
