Exercise reduces GABA synaptic input onto nucleus tractus solitarii baroreceptor second-order neurons via NK1 receptor internalization in spontaneously hypertensive rats.
Exercise reduces GABA synaptic input onto nucleus tractus solitarii baroreceptor second-order neurons via NK1 receptor internalization in spontaneously hypertensive rats.
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运动可通过自发性高血压大鼠的NK1受体内在化来减少GABA突触输入到Solartoctus silitarii solitarii soloreceptor二阶神经元上。
DOI：
10.1523/jneurosci.4413-08.2009
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发表时间：
2009-03-04
期刊：
影响因子：
--
通讯作者：
Bonham AC
中科院分区：
文献类型：
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作者：
Chen CY;Bechtold AG;Tabor J;Bonham AC
单次轻度至中度运动可导致高血压受试者运动后血压降低，即运动后低血压（PEH）。PEH的完全表达需要功能性压力反射、高血压和肌肉传入（运动）的激活，这表明调节运动和血压的神经网络中的相互作用导致血压下降。孤束核（NTS）是第一个接收来自携带血压和肌肉活动信息的神经的输入的大脑部位，使其成为整合心血管反应的理想部位。在运动过程中，肌肉传入兴奋NTS GABA神经元通过P物质和微量注射P物质-神经激肽1受体（NK 1-R）拮抗剂到NTS减弱PEH。这些数据表明，P物质NK 1-R和GABA能传输之间的相互作用，在NTS可能有助于PEH。我们对自发性高血压大鼠（SHR）的孤束核压力感受器二级神经元进行了电压钳制。所有动物在30分钟内处死，并在假手术/运动方案后2-8小时进行膜片钳记录。结果表明：1）单次运动可降低GABA自发抑制性突触电流（sIPC）的频率，但幅度不降低; 2）内源性P物质对sIPSC频率的影响; 3）sIPSC对外源性P物质的频率反应。这些数据表明，运动诱导的NK 1-R内化的结果在压力感受性反射通路中的神经元减少的内在抑制性输入。
A single bout of mild to moderate exercise can lead to a post-exercise decrease in blood pressure in hypertensive subjects, namely post-exercise hypotension (PEH). The full expression of PEH requires a functioning baroreflex, hypertension and activation of muscle afferents (exercise), suggesting that interactions in the neural networks regulating exercise and blood pressure result in this fall in blood pressure. The nucleus tractus solitarii (NTS) is the first brain site that receives inputs from nerves carrying blood pressure and muscle activity information, making it an ideal site for integrating cardiovascular responses to exercise. During exercise, muscle afferents excite NTS GABA neurons via substance P and microinjection of a substance P-neurokinin 1 receptor (NK1-R) antagonist into the NTS attenuates PEH. The data suggest that an interaction between the substance P NK1-R and GABAergic transmission in the NTS may contribute to PEH. We performed voltage-clamping on NTS baroreceptor second-order neurons in spontaneously hypertensive rats (SHRs). All animals were sacrificed within 30 min and the patch-clamp recordings were performed 2-8 hr after the sham/exercise protocol. The data showed that a single bout of exercise reduces 1) the frequency but not the amplitude of GABA spontaneous inhibitory synaptic currents (sIPCs), 2) endogenous substance P influence on sIPSC frequency, and 3) sIPSC frequency response to exogenous application of substance P. Furthermore, immunofluorescence labeling in NTS show an increased substance P NK1-R internalization on GABA neurons. The data suggest that exercise-induced NK1-R internalization results in a reduced intrinsic inhibitory input to the neurons in the baroreflex pathway.