The Role of the Paratrigeminal Nucleus in Vagal Afferent Evoked Respiratory Reflexes: A Neuroanatomical and Functional Study in Guinea Pigs.
The Role of the Paratrigeminal Nucleus in Vagal Afferent Evoked Respiratory Reflexes: A Neuroanatomical and Functional Study in Guinea Pigs.
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DOI：
10.3389/fphys.2015.00378
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发表时间：
2015
影响因子：
4
通讯作者：
McGovern AE
中科院分区：
文献类型：
--
作者：
Driessen AK;Farrell MJ;Mazzone SB;McGovern AE
呼吸树接受颈静脉和结节迷走神经节的感觉神经支配。这些神经节的神经元来源于胚胎学上不同的起源，因此表现出不同的分子、神经化学和生理表型。此外，尽管结节性传入神经元投射到孤立束核（nTS），但最近对大鼠的神经解剖学研究表明，颈静脉神经元的中枢末端位于股旁核（Pa5）。在目前的研究中，我们证实豚鼠在结节和颈神经节传入事件的脑干末端之间表现出可比的区别。因此，将荧光共轭霍乱毒素B （CT-B）神经示踪剂显微注射到尾侧nTS和Pa5中，分别在结节和颈状神经节中产生高度特异性的逆行标记。结节神经元多表达160 KD神经丝蛋白和Na+/K+ atp酶的α 3亚基，颈静脉神经元多表达P物质（SP），尤其是降钙素基因相关肽（CGRP）。事实上，与nTS相比，Pa5的末端纤维的特点是CGRP的表达显著增加，这进一步支持了颈静脉传入投射到三叉相关脑干区域的观点。在选择性切除喉部结节传入神经后对豚鼠喉部进行电刺激（保留颈静脉神经），导致刺激依赖性呼吸减慢和最终的呼吸暂停。双侧向nTS注射GABAA激动剂muscimol不影响颈神经节神经元介导的反应，但向Pa5注射muscimol可消除这种反应。综上所述，这些数据证实了颈状和结节状迷走神经节传入神经元支配不同的中枢回路，并支持了多个外周和中枢通路介导与气道刺激相关的感觉反应的观点。
The respiratory tree receives sensory innervation from the jugular and nodose vagal sensory ganglia. Neurons of these ganglia are derived from embryologically distinct origins and as such demonstrate differing molecular, neurochemical and physiological phenotypes. Furthermore, whereas nodose afferent neurons project to the nucleus of the solitary tract (nTS), recent neuroanatomical studies in rats suggest that jugular neurons have their central terminations in the paratrigeminal nucleus (Pa5). In the present study we confirm that guinea pigs demonstrate a comparable distinction between the brainstem terminations of nodose and jugular ganglia afferents. Thus, microinjection of fluorescently conjugated cholera toxin B (CT-B) neural tracers into the caudal nTS and Pa5 resulted in highly specific retrograde labeling of neurons in the nodose and jugular ganglia, respectively. Whereas, nodose neurons more often expressed 160 KD neurofilament proteins and the alpha3 subunit of Na+/K+ ATPase, significantly more jugular neurons expressed the neuropeptides substance P (SP) and, especially, Calcitonin Gene-Related Peptide (CGRP). Indeed, terminal fibers in the Pa5 compared to the nTS were characterized by their significantly greater expression of CGRP, further supporting the notion that jugular afferents project to trigeminal-related brainstem regions. Electrical stimulation of the guinea pig larynx following selective surgical denervation of the nodose afferent innervation to the larynx (leaving intact the jugular innervation) resulted in stimulus dependent respiratory slowing and eventual apnea. This jugular ganglia neuron mediated response was unaffected by bilateral microinjections of the GABAA agonist muscimol into the nTS, but was abolished by muscimol injected into the Pa5. Taken together these data confirm that jugular and nodose vagal ganglia afferent neurons innervate distinct central circuits and support the notion that multiple peripheral and central pathways mediate sensory responses associated with airway irritations.