Vestibular neurons with direct projections to the solitary nucleus in the rat
Vestibular neurons with direct projections to the solitary nucleus in the rat
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DOI：
10.1152/jn.00082.2019
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发表时间：
2019-08-01
影响因子：
2.5
通讯作者：
Holstein, Gay R.
中科院分区：
文献类型：
--
作者：
Gagliuso, Amelia H.;Chapman, Emily K.;Holstein, Gay R.
用顺行和逆行追踪结合神经递质和调节剂免疫标记方法，对大鼠前庭核神经元与孤束核直接投射的化学解剖进行了研究。观察到前庭尾侧核神经元向孤束核的直接、稀疏分支但高度曲张的轴突投射。产生这些投射的前庭神经元主要位于同侧前庭内侧核。胞体呈强烈的谷氨酸免疫荧光，其轴突含有囊泡状谷氨酸转运蛋白2，支持细胞利用谷氨酸进行神经传递的解释。谷氨酸免疫荧光逆行填充的前庭细胞还含有神经调节剂咪唑乙酸核糖核酸，这是一种参与血压调节的内源性中枢神经系统配体。前庭孤立神经元被轴体GABA能终末包裹，表明它们受到严格的抑制控制。这些结果为孤束核尾侧和中间区域的前庭输出通路的一过性激活奠定了化学解剖学基础。这样，头部静止位置的变化和头部在空间中的运动可能会直接影响心率、血压。呼吸，以及胃肠运动。这将为外周前庭激活后观察到的同步心率和血压反应，以及从神经源性直立性低血压、体位性直立性心动过速综合征和血管迷走性晕厥到与运动病相关的恶心和呕吐等疾病提供一种解剖学解释。新发现和值得注意的前庭神经元直接投射到孤束核的前庭神经元利用谷氨酸进行神经传递，并受咪唑乙酸核苷的调节。这是对前庭-孤立性通路的化学神经解剖学的第一次直接演示。
Anterograde and retrograde tract tracing were combined with neurotransmitter and modulator immunolabeling to identify the chemical anatomy of vestibular nuclear neurons with direct projections to the solitary nucleus in rats. Direct, sparsely branched but highly varicose axonal projections from neurons in the caudal vestibular nuclei to the solitary nucleus were observed. The vestibular neurons giving rise to these projections were predominantly located in ipsilateral medial vestibular nucleus. The cell bodies were intensely glutamate immunofluorescent, and their axonal processes contained vesicular glutamate transporter 2, supporting the interpretation that the cells utilize glutamate for neurotransmission. The glutamate-immunofluorescent, retrogradely filled vestibular cells also contained the neuromodulator imidazoleacetic acid ribotide, which is an endogenous CNS ligand that participates in blood pressure regulation. The vestibulo-solitary neurons were encapsulated by axo-somatic GABAergic terminals, suggesting that they are under tight inhibitory control. The results establish a chemoanatomical basis for transient vestibular activation of the output pathways from the caudal and intermediate regions of the solitary nucleus. In this way, changes in static head position and movement of the head in space may directly influence heart rate, blood pressure. respiration, as well as gastrointestinal motility. This would provide one anatomical explanation for the synchronous heart rate and blood pressure responses observed after peripheral vestibular activation, as well as disorders ranging from neurogenic orthostatic hypotension, postural orthostatic tachycardia syndrome, and vasovagal syncope to the nausea and vomiting associated with motion sickness.NEW & NOTEWORTHY Vestibular neurons with direct projections to the solitary nucleus utilize glutamate for neurotransmission, modulated by imidazoleacetic acid ribotide. This is the first direct demonstration of the chemical neuroanatomy of the vestibulo-solitary pathway.