Integrate Analysis of Blood Pressure Regulation System in CNS.

颈动脉窦对血压的反射通过位于主动脉弓的主动脉降压神经（ADN）的压力感受器神经末梢传递到孤立束核（NTS）。然而，ADN投射的NTS神经元突触传递的详细机制以及血管舒缩反射的调节机制尚不清楚。在本研究中，将Di-1注射到分离的ADN后3-5天，可以鉴定出ADN投射的NTS神经元。来自结节神经节的ADN轴突进入脑干形成孤立束（ST），终止内侧NTS神经元的胞体和树突，释放谷氨酸。鉴定的内侧NTS神经元对盐的敏感性是ADN非投射神经元的2倍。ST诱发的单突触谷氨酸能反应是由NTS内侧神经元的非nmda谷氨酸受体介导的。此外，辣椒素（VR-1（香草素）受体激动剂）和a， b与嘌呤能P2X3受体激动剂（ATP）相结合，在游离的内侧NTS神经元中增加了30倍的谷氨酸释放，这表明辣椒素和ATP在脑干水平上调控了血管舒张。由于NTS暴露于开放的血脑屏障，这种功能性VR-1和嘌呤能调节可能在任何系统性治疗中发挥重要作用。

The carotid sinus reflex of the blood pressure is transmitted to the nucleus of the solitary tract (NTS) via baroreceptor nerve terminals in the aortic depressor nerve (ADN) which is located in the aortic arch. However, not only the detailed mechanisms on synapse transmission in the NTS neurons projected from ADN but also modulations of vasomotor reflex have not been clarified.In the present studies, the NTS neurons projected from ADN were identified 3-5 days after injection of Di-1 to the separated ADN.This ADN axon from nodose ganglion entered the brainstem to form the solitary tract (ST) and terminated the soma and dendrites of medial NTS neurons, which released glutamate. The identified medial NTS neurons were sensitive to kainate application by 2-fold relative to the non-projected neurons from ADN.ST evoked mono-synaptic glutamatergic responses were mediated by non-NMDA glutamate receptors in the medial NTS neurons. Furthermore, both capsaicin, a VR-1 (vanilloid) receptors agonist and a, b met ATP, a purinergic P2X3 receptors agonist, increased glutamate release 30-fold relative to the control value in dissociated medial NTS neurons, Which is suggested that vasodilation is manipulated capsaicin and ATP at brainstem level.This functional VR-1 and purinergic regulation might play an important role for any systemic therapies since NTS is exposed to an open blood brain barrier.