Activity of neurons located in the region of the hypoglossal motor nucleus during swallowing in sheep
Activity of neurons located in the region of the hypoglossal motor nucleus during swallowing in sheep
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绵羊吞咽过程中舌下运动核区域神经元的活动
DOI：
10.1007/bf00247040
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发表时间：
2004
影响因子：
2
通讯作者：
M. Amri
中科院分区：
文献类型：
--
作者：
A. Car;M. Amri
研究了氟烷麻醉绵羊舌下运动核（XIIth）吞咽神经元的胞外活动。86例SN表现出与喉上神经刺激引起的geniohyoïd （GH）肌吞咽肌电图（EMG）活动密切相关的放电。吞咽活动在运动麻痹后持续存在，表明这种活动不是由感觉反馈引起的。将SN分为两组。第1组SN（N = 66）在50 ~ 300 ms的GH响应期间释放了多达12个尖峰的爆发。平均频率范围为10 ~ 60hz，峰值瞬时频率范围为10 ~ 100hz。32例SN通过刺激第xii神经反日激活。SN向第xii神经内支和外侧支发送的轴突反峰平均潜伏期分别为2.6 ms和2.4 ms，对应的传导速度分别为50.4 m/s和53.7 m/s。另外34个第1组SN位于对映场电位较大的位点，模糊了单一对映峰的识别。30例第1组SN， 16例反日激活，14例大场电位区，在组织学上位于第12运动核，位于距臀部1 mm至2 mm的横平面之间。第一组SN可能是供给GH和舌肌的运动神经元。II组SN（N = 20）未被XIIth神经刺激反向激活，且均位于XIIth运动核外侧边缘附近的网状结构，尤其位于距臀部1mm以内的横平面。在吞咽过程中，II组SN表现出持续100 - 370 ms的激活（10-50个峰），通常在GH活性开始之前开始。平均频率范围为60 ~ 200hz，峰值瞬时频率范围为120 ~ 400hz。与直接刺激XIIth运动核相比，II组中枢微刺激在同侧XIIth神经中诱发的突触电位延长0.8 ~ 1.3 ms。此外，II组SN刺激也能有效激发对侧GH的肌电活动。这些结果表明，II组SN是参与双侧GH和舌肌激活的中间神经元。
Extracellular activity of swallowing neurons (SN) in the region of the hypoglossal (XIIth) motor nucleus was studied in sheep anesthetized with halothane. Eighty six SN exhibited a discharge closely linked to swallowing electromyographic (EMG) activity of the geniohyoïd (GH) muscle induced by stimulation of the superior laryngeal nerve. Swallowing activation persisted after motor paralysis, indicating that this activity did not result from sensory feedback. SN were classified into two groups.Group I SN(N = 66) discharged a burst of up to 12 spikes for 50–300 ms during the response of GH. Mean frequencies ranged from 10 to 60 Hz, peak instantaneous frequencies from 10 to 100 Hz. Thirty two SN were antidromically activated by stimulating the XIIth nerve. Mean latencies of antidromic spikes were 2.6 ms and 2.4 ms for SN sending their axons in the medial and lateral branches respectively of XIIth nerve, corresponding to conduction velocities of 50.4 m/s and 53.7 m/s. The other 34 group I SN were located at sites with large antidromic field potentials obscuring the identification of unitary antidromic spikes. Thirty group I SN, 16 antidromically activated and 14 in areas with large field potentials, were histologically located in the XIIth motor nucleus between the transverse planes 1 mm caudal to 2 mm rostral to the obex. Group I SN are likely motoneurons supplying GH and tongue musculature.Group II SN(N = 20) were never antidromically activated by XIIth nerve stimulation, and were all located in the reticular formation adjacent to the lateral edge of the XIIth motor nucleus, particularly in transverse planes within 1 mm of the obex. During swallowing, group II SN exhibited an activation (10–50 spikes) lasting from 100 to 370 ms and generally starting before the onset of GH activity. Mean frequencies ranged from 60 to 200 Hz, and peak instantaneous frequencies from 120 to 400 Hz. Central microstimulation of group II SN evoked in the ipsilateral XIIth nerve a synaptic potential with a latency 0.8 to 1.3 ms longer than that induced by directly stimulating the XIIth motor nucleus. In addition, stimulation of group II SN was also effective in eliciting EMG activity of the contralateral GH. These results suggest that group II SN are interneurons involved in the bilateral activation of GH and tongue muscles.