Dampney Roger A L
Physiology, School of Medical Sciences, The University of SydneySydney, NSW, Australia.
Front Neurosci. 2017 Aug 15;11:461. doi: 10.3389/fnins.2017.00461. eCollection 2017.
The baroreceptor reflex controls arterial pressure primarily via reflex changes in vascular resistance, rather than cardiac output. The vascular resistance in turn is dependent upon the activity of sympathetic vasomotor nerves innervating arterioles in different vascular beds. In this review, the major theme is that the baroreflex control of sympathetic vasomotor activity is not constant, but varies according to the behavioral state of the animal. In contrast to the view that was generally accepted up until the 1980s, I argue that the baroreflex control of sympathetic vasomotor activity is not inhibited or overridden during behaviors such as mental stress or exercise, but instead is reset under those conditions so that it continues to be highly effective in regulating sympathetic activity and arterial blood pressure at levels that are appropriate for the particular ongoing behavior. A major challenge is to identify the central mechanisms and neural pathways that subserve such resetting in different states. A model is proposed that is capable of simulating the different ways in which baroreflex resetting is occurred. Future studies are required to determine whether this proposed model is an accurate representation of the central mechanisms responsible for baroreflex resetting.
压力感受器反射主要通过血管阻力的反射性变化而非心输出量来控制动脉血压。血管阻力又取决于支配不同血管床中小动脉的交感缩血管神经的活动。在这篇综述中，主要观点是压力感受器对交感缩血管活动的控制并非恒定不变，而是根据动物的行为状态而变化。与直到20世纪80年代普遍接受的观点相反，我认为在精神压力或运动等行为过程中，压力感受器对交感缩血管活动的控制并未受到抑制或被超越，而是在这些情况下进行了重新设定，以便它在适合特定当前行为的水平上继续高效调节交感活动和动脉血压。一个主要挑战是确定在不同状态下实现这种重新设定的中枢机制和神经通路。提出了一个能够模拟压力感受器重新设定发生的不同方式的模型。未来的研究需要确定这个提出的模型是否准确代表了负责压力感受器重新设定的中枢机制。
