Differential responses of sympathetic premotor neurons in the rostral ventrolateral medulla to stimulation of the dorsomedial hypothalamus in rabbits

作者：Wang Rong; Koganezawa Tadachika; Terui Naohito^*

来源：Brain Research, 2010, 1356: 44-53.

DOI：10.1016/j.brainres.2010.08.024

• Rostral ventrolateral medulla
• Defense response
• Regional different response
• Sympathetic nervous system
• Dorsomedial hypothalamus

Electrical stimulation of the posterior dorsomedial hypothalamus (DMH) elicits a defense response, including vasodilation in the skeletal muscles and vasoconstriction in the viscera. To examine whether sympathetic premotor neurons in the rostral ventrolateral medulla (RVLM) participate in these differential vascular responses, RVLM neuron activity, renal sympathetic nerve activity (RSNA), renal vessel conductance (RVC), skeletal muscular vessel conductance (MVC), arterial pressure (AP), and heart rate (HR) were simultaneously measured in urethane-anesthetized, vagotomized, and immobilized rabbits. Electrical stimulation of the DMH increased RSNA, MVC, AP, and HR but decreased RVC. The RVLM neurons were classified into three groups according to their responses to tetanic (10 s) stimulation of the DMH. Twenty neurons (Type I) were excited, 17 (Type II) were inhibited, and 2 (Type III) did not respond. To the short-train (100 ms) stimulation, all of the Type I neurons showed excitation; in contrast, 12 Type II neurons showed biphasic response that was early excitation followed by inhibition. The remainder showed only inhibition. Type III neurons also did not respond to the short-train stimulation. These results indicated that regional differences in responses of sympathetic nerves in the defense response are supported by functional differentiation of sympathetic premotor neurons in the RVLM.

• 出版日期2010-10-14