Transmission pathways in the rat superior cervical ganglion

Abstract

On isolated preparations of the superior cervical ganglion (SCG, n = 8) taken from 21-day-old rats, we studied the intraganglion pathways and mechanisms underlying generation of synaptic responses of SCG neurons to antidromic stimulation. One of the three nerves connected with the SCG was stimulated, and compound action potentials were recorded simultaneously from the other two nerves; then, the order of stimulated and recorded nerves was changed. Orthodromic stimulation of the cervical sympathetic nerve (CSN) evoked responses in the internal carotid nerve (ICN), which could be completely blocked by hexamethonium, and responses in the external carotid nerve (ECN), which contained a component that was not blocked by this agent. Antidromic stimulation of the ICN did not induce responses in the CSN and ECN, whereas stimulation of the ECN caused responses in the CSN, which were not blocked by hexamethonium. Effects of superfusion of the SCG with a Ca 2+ -free solution allowed us to conclude that the hexamethonium-insensitive component of the responses in the CSN and ECN and ECN−CSN conduction can be explained by the presence of direct fibers going from the CSN to the ECN with no synaptic relay. Possible mechanisms underlying antidromic stimulation-induced synaptic responses in SCG neurons are discussed.

Review of the external carotid plexus: anatomy, function, and clinical manifestations

“…Activation of all facial glands does not likely occur upon solely stimulating the external carotid nerves. Specifically, research on rat superior cervical ganglia has discovered that though the cervical sympathetic nerve may excite both the external and internal carotid nerves, stimulation of either the internal or external carotid nerves only initiates antidromic effects on the cervical sympathetic nerve www.acbjournal.org https://doi.org/10.5115/acb.20.308 [3]. Transmission of action potentials is not typically transferred from the external carotid nerve to the internal carotid nerve or vice versa [3].…”

“…Specifically, research on rat superior cervical ganglia has discovered that though the cervical sympathetic nerve may excite both the external and internal carotid nerves, stimulation of either the internal or external carotid nerves only initiates antidromic effects on the cervical sympathetic nerve www.acbjournal.org https://doi.org/10.5115/acb.20.308 [3]. Transmission of action potentials is not typically transferred from the external carotid nerve to the internal carotid nerve or vice versa [3]. Additionally, nerve fibers travel from the cervical sympathetic nerve through the superior cervical ganglion and to the external carotid nerve with no synaptic relay [3].…”

“…1 and 2 ) encapsulates the external carotid artery and its branches to innervate the majority of the mid and lower face [ 1 ]. The superior pole of the superior cervical ganglion gives rise to postganglionic sympathetic fibers of which some of these branches form connections along the external carotid artery and combine as the external carotid plexus [ 2 , 3 ]. Generally, the anterior communicating branch of the superior cervical ganglion to the external carotid artery travels directly to the medial side of the external carotid artery [ 2 , 4 ].…”

“…Whereas another branch, the interior communicating branch of the superior cervical ganglion to the superior laryngeal nerve, travels inferiorly and wraps around the superior thyroid artery (STA) before returning superiorly to anastomose with the prior branch to the external carotid artery [ 2 , 5 ] Branches of the plexus partially continue onto the branches of the external carotid artery. As a result, implications to the plexus or nearby artery may result in neural abnormalities to facial muscles and sweat glands [ 3 ]. As this plexus is poorly described in the literature, the present paper aims to review the anatomy, function, and clinical applications of the external carotid plexus for a better understanding among anatomists and clinicians alike.…”

Synaptic Responses of Superior Cervical Ganglion Neurons of Rats With Experimental Diabetes Mellitus

“…Федулова, М.С. Веселовський потенціалів дії в нейронах ВШГ здійснюється за допомогою холінергічної передачі та активації нейрональних нікотинових ацетилхолінових рецепторів [4,7]. Амплітуда ЗПСП та показники блокуючої дії бензогексонію у контрольній групі щурів статистично не відрізнялися від значень у щурів з ЦД.…”