THE NEURAL PATHWAY INVOLVED IN EFFERENT INHIBITION OF CHEMORECEPTORS IN THE CAT CAROTID-BODY
THE NEURAL PATHWAY INVOLVED IN EFFERENT INHIBITION OF CHEMORECEPTORS IN THE CAT CAROTID-BODY
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DOI：
10.1002/cne.902010310
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发表时间：
1981-01-01
影响因子：
2.5
通讯作者：
MITCHELL, RA
中科院分区：
文献类型：
--
作者：
MCDONALD, DM;MITCHELL, RA
研究了颈动脉窦神经中传出轴突的通路是否是传出抑制（通过电刺激颈动脉窦神经在颈动脉体化学感受器中诱导的抑制）所必需的。猫颈动脉窦神经的传出轴突被消除，而不破坏感觉轴突。这是通过切断同侧舌咽神经和迷走神经的感觉神经节和/或通过去除结节和上级颈神经节来实现的。在神经生理学研究中，手术后10天猫的化学感受器的反应与对照组相同。化学感受器的活动减少，电刺激颈动脉窦神经，增加缺氧和氰化物。在手术猫在对照组动物，传出抑制被取消氟哌啶醇和二氢麦角胺，药物阻断多巴胺的抑制作用。EM研究表明，在控制和实验颈动脉体中，血管球细胞/鞘细胞复合体中的神经末梢数量没有明显差异。在颈动脉窦神经被切断后[10天]，靠近这些细胞的神经末梢的数量减少了> 99%。切断神经根和切除神经节消除了血管上的大多数神经末梢：去甲肾上腺素能型神经末梢的数量减少了99%，其他类型的神经末梢（假定的胆碱能和肽能类型）减少了> 90%。通过破坏从结状神经节、上级颈神经节或从脑干中的神经元（其轴突在舌咽神经或迷走神经中延伸）到血管和颈动脉体球细胞的输入，传出抑制可能不会被消除。传出抑制可能由感觉轴突的逆向刺激引起。
Whether a pathway of efferent axons in the carotid sinus nerve is necessary for efferent inhibition (inhibition induced in carotid body chemoreceptors by electrical stimulation of the carotid sinus nerve) is studied. Efferent axons in the carotid sinus nerve of cats were eliminated without destroying the sensory axons. This was achieved by cutting the ipsilateral glossopharyngeal and vagus nerves central to their sensory ganglia and/or by removing the nodose and superior cervical ganglia. In neurophysiological studies, the response of chemoreceptors in cats 10 days after surgery was the same as that in controls. Chemoreceptor activity was decreased by electrical stimulation of the carotid sinus nerve and was increased by hypoxia and cyanide. In operated cats as in control animals, efferent inhibition was abolished by haloperidol and dihydroergotamine, drugs that block the inhibitory action of dopamine. EM studies disclosed that the number of nerve endings in glomus cell/sheath cell complexes was not measurably different in control and experimental carotid bodies. After the carotid sinus nerve was cut [10 days] the number of nerve endings next to such cells was reduced by > 99%. Cutting the nerve roots and excising the ganglia eliminated most nerve endings on blood vessels: the number of noradrenergic-type nerve endings was reduced by 99% and other types of nerve endings (presumptive cholinergic and peptidergic types) were reduced > 90%. Efferent inhibition probably is not abolished by operations that destroy inputs to blood vessels and to carotid body glomus cells from the nodose ganglion, superior cervical ganglion or from neurons in the brain stem whose axons run in the glossopharyngeal or vagus nerves. Efferent inhibition may be caused by antidromic stimulation of sensory axons.