Dean C, Seagard J L, Hopp F A, Kampine J P
Department of Anesthesiology, Medical College of Wisconsin, Milwaukee.
J Auton Nerv Syst. 1992 Jan;37(1):1-10. doi: 10.1016/0165-1838(92)90139-8.
A rise in arterial blood pressure can be evoked by microinjections of D,L-homocysteic acid into localized regions of the ventrolateral medulla of the cat. Three patterns of sympathetic discharge can be identified during the pressor response. A differential pattern consisting of an increase in renal nerve activity and no change in sympathetic activity to skeletal muscle vasculature can be elicited from sites ventromedial to the caudal pole of the facial nucleus. From more lateral and caudal sites, a generalized sympatho-excitation is evoked in the outflow to both the kidney and hindlimb muscle vasculature. A third response consisting of a differential increase in muscle sympathetic activity simultaneous with a small decrease in renal nerve activity could be evoked from caudal sites, lateral to the inferior olives and superficial to the ventral surface. The results show that ventral medullary neurons can selectively activate sympathetic outflow to control specific vascular beds. These data may support the hypothesis that the ventrolateral medulla contains discrete groups of topographically arranged neurons that can differentially control sympathetic tone to various end-organs.
向猫延髓腹外侧的局部区域微量注射D，L-高半胱氨酸可引起动脉血压升高。在升压反应过程中可识别出三种交感神经放电模式。从面神经核尾极腹内侧的部位可引出一种差异模式，即肾神经活动增加，而对骨骼肌血管系统的交感神经活动无变化。从更外侧和尾侧的部位，在肾脏和后肢肌肉血管系统的传出神经中可诱发全身性交感神经兴奋。从下橄榄核外侧和腹表面浅层的尾侧部位可引出第三种反应，即肌肉交感神经活动差异性增加，同时肾神经活动略有减少。结果表明，延髓腹侧神经元可选择性激活交感神经传出，以控制特定的血管床。这些数据可能支持这样一种假说，即延髓腹外侧包含按拓扑结构排列的离散神经元群，它们可差异性地控制对各种终末器官的交感神经张力。
