Mochida A
Department of Otorhinolaryngology and Physiology, School of Medicine, Chiba University.
Nihon Jibiinkoka Gakkai Kaiho. 1990 Jun;93(6):938-48. doi: 10.3950/jibiinkoka.93.938.
Electromyographic (EMG) responses of the intrinsic laryngeal muscle have been investigated to clarify reflexogenic laryngeal controls from a viewpoint of its functional significance during phonation. Twenty-five adult cats were anesthetized with intraperitoneal injection of 4ml/kg of a mixture of 10% urethane and 1% alpha-chloralose. Either the internal branch of the superior laryngeal nerve (ISLN) or the recurrent laryngeal nerve (RLN) was carefully dissected and central end of the dissected nerve was electrically stimulated. EMG of the contra-lateral Thyro-Arytenoid muscle (TA muscle) to the stimulation was recorded using a hooked-wire electrode inserted through the laryngeal mucosa. EMG of the TA muscle evoked by the stimulation of the ISLN were analyzed with respect to its latency and discharge pattern inter-collicular brainstem transsected. Together with the stimulation of the RLN, vibratory stimuli were given mainly to the subglottic mucosa as conditioning stimuli. The vibratory frequency was changed from 50Hz to 400Hz step-wisely. Following results were obtained. 1. EMG response of the contra-lateral TA muscle to the stimulation of the ISLN showed two different kinds of latency, approximately 8-10msec, and 40-60msec. 2. After inter-collicular brainstem transsection, evoked response of the latter disappeared. This result indicates that the ISLN-RLN reflex loop consisted of more than two routes, different in the number of synaptic junctions. 3. The vibratory stimuli given to the laryngeal mucosa had facilitatory effect on the reflexive EMG response evoked by the stimulation of the RLN. 4. This facilitatory effect of the vibratory stimuli disappeared after topical anesthesia of the laryngeal mucosa. 5. The facilitatory effect on the reflex responses was partially increased depending on the vibratory frequencies applied. In conclusion, vibratory stimuli to the laryngeal mucosa reflexively modulate the activity of the intrinsic laryngeal muscles.
为了从发声过程中喉内肌反射性控制的功能意义角度进行阐明，人们对喉内肌的肌电图（EMG）反应进行了研究。25只成年猫通过腹腔注射4ml/kg的10%氨基甲酸乙酯和1%水合氯醛混合物进行麻醉。仔细解剖喉上神经内支（ISLN）或喉返神经（RLN），并对解剖神经的中枢端进行电刺激。使用通过喉黏膜插入的钩状线电极记录对侧甲状杓肌（TA肌）对刺激的EMG。分析了在中脑间脑干横断后，ISLN刺激诱发的TA肌EMG的潜伏期和放电模式。与RLN刺激一起，主要对声门下黏膜给予振动刺激作为条件刺激。振动频率从50Hz逐步改变到400Hz。获得了以下结果。1. 对侧TA肌对ISLN刺激的EMG反应表现出两种不同的潜伏期，约8 - 10毫秒和40 - 60毫秒。2. 中脑间脑干横断后，后者的诱发反应消失。该结果表明ISLN - RLN反射环由两条以上不同突触连接数量的途径组成。3. 给予喉黏膜的振动刺激对RLN刺激诱发的反射性EMG反应有促进作用。4. 喉黏膜局部麻醉后，这种振动刺激的促进作用消失。5. 对反射反应的促进作用部分地随着所施加的振动频率而增加。总之，对喉黏膜的振动刺激可反射性调节喉内肌的活动。
