Gauthier P, Barillot J C, Dussardier M
J Physiol (Paris). 1980 Nov;76(6):647-61.
Activities of single efferent fibres which innervate the laryngeal muscles in adult cats were studied during repetitive stimulation of the recurrent laryngeal nerve or the vagus nerve. The orthodromic response (primary response) can be followed by another response (secondary response) which has a latence consistant with the hypothesis of a central origin. This secondary response has an irregular incidence of occurrence, about 5.6 time for 100 stimulations. This secondary response: 1. Is present for 90% of the tested inspiratory or expiratory laryngeal fibres; 2. Depends on a central origin because it no longer occurs when the cervical vagus nerve is cut rostral to the site of stimulation; 3. Is not the consequence of the stimulation of afferent fibres because it is not altered by destruction of the centripetal vagal pathway (Fig. 4); 4. Can be obtained by the stimulation of other branches than those containing the recorded fibre (Fig. 2), so it is not necessarily the consequence of the antidromic invasion of this fibre; 5. Depends on a cholinergic synapse because it is more frequently observed after intra-arterial injection of acetylcholine (Fig. 6) and disappears after injection of Mecamylamine (an antinicotinic drug) (Fig. 7); 6. Persists after injection of strychnine and becomes more frequently observed; hence it does not seem to be associated with a disinhibitory mechanism; 7. Depends on a phenomenon of convergence because it occurred more frequently when the amplitude of stimulation was increased (Fig. 3); 8. Has a central delay which seems not to be consistent with an electrotonic origin; 9. Can be recorded from an inspiratory fibre when stimulating the remaining inspiratory or expiratory fibres. A secondary response can also be recorded from an expiratory fibre by stimulating the same or other expiratory fibres, but not after excitation of inspiratory fibres (Fig. 5). These results suggest: (1) a functional organisation into the pool of laryngeal motoneurones; (2) the possible existence of intrabulbar axonal collaterals in that pool.
在成年猫的喉返神经或迷走神经重复刺激过程中，研究了支配喉肌的单根传出纤维的活动。顺向反应（初级反应）之后可能会出现另一种反应（次级反应），其潜伏期符合中枢起源的假说。这种次级反应的出现频率不规则，每100次刺激约出现5.6次。这种次级反应：1. 在90%的受试吸气或呼气喉纤维中存在；2. 依赖于中枢起源，因为当在刺激部位近端切断颈迷走神经时，它不再出现；3. 不是传入纤维刺激的结果，因为它不会因向心性迷走神经通路的破坏而改变（图4）；4. 通过刺激包含记录纤维的分支以外的其他分支也可获得（图2），所以它不一定是该纤维逆向侵入的结果；5. 依赖于胆碱能突触，因为在动脉内注射乙酰胆碱后更频繁地观察到它（图6），而在注射美加明（一种抗烟碱药物）后消失（图7）；6. 注射士的宁后持续存在且更频繁地被观察到；因此它似乎与去抑制机制无关；7. 依赖于汇聚现象，因为当刺激幅度增加时它更频繁地出现（图3）；8. 有一个中枢延迟，似乎与电紧张起源不一致；9. 在刺激其余吸气或呼气纤维时，可以从吸气纤维记录到次级反应。通过刺激相同或其他呼气纤维，也可以从呼气纤维记录到次级反应，但在吸气纤维兴奋后则不能（图5）。这些结果表明：（1）喉运动神经元池存在功能组织；（2）该池中可能存在延髓内轴突侧支。
