Electrophysiological analysis of the lateral reticular formation subserving autonomic and motor oral functions

通过解剖学、电生理学和行为学研究，研究了神经网络在脑干辅助自主神经和运动口腔功能中的作用。在解剖学研究中，将辣根过氧化物酶注射到大鼠舌前部或舌索神经，观察到支配舌的上唾液神经元以及支配颌下腺和舌下腺的上唾液神经元。两组SS神经元形态相似，混杂在外侧网状结构中。在电生理研究中，采用全细胞膜片钳技术分析脑干切片中SS神经元的生物物理特性。支配舌的SS神经元显示一个显著的瞬时外向电流(A-电流)，并发出高达70赫兹的电流。那些支配唾液腺的人表现出持续时间较长的A电流，并发出高达30赫兹的电流。在行为学研究中，唾液从颌下腺和…流出在自由活动的大鼠中，慢性记录到更多的咬肌活动。在咀嚼过程中，唾液量和肌肉活动并不总是平行的，这表明离心力对自主神经和运动功能的影响不同。当被拒绝的味觉物质注射到口腔中时，伴随着强烈的唾液，诱导出节律性的肌肉活动。这种行为也发生在去大脑的动物身上，这表明这种行为的反射位于脑干下部。当摘除唾液腺时，咀嚼时的下巴运动变得不规则，鼓索神经的味觉敏感度下降。通过这些研究，我们得出结论，自主神经和运动口腔功能受控于较高的中枢神经系统，但这两种功能在下脑干特别是外侧网状结构中存在一个接触点。应分析三叉神经运动核前运动神经元的活动，并与SS神经元的活动进行比较。较少

Neural network in the brainstem subserving autonomic and motor oral functions was investigated by anatomical, electrophysiological and behavioral studies. In the anatomical study, horseradish peroxidase was injected into the anterior part of the tongue or the chorda-lingual nerve and the superior salivatory (SS) neurons innervating the tongue and those innervating the submandibular and sublingual salivary glands were identified in rats. The two groups of SS neurons were similar in shape and intermingled in the lateral reticular formation. In the electrophysiological study, biophysical properties of the SS neurons were analyzed by the whole-cell patch clamp technique in sliced brainstem preparations. The SS neurons innervating the tongue displayd a prominent transient outward current (A-current), and fired up to 70 Hz. Those innervating the salivary glands expressed A-current lasting longer period, and fired up to 30 Hz. In behavioral study, salivary flow from the submandibular gland an … More d activity of the masseter muscle were chronically recorded from the freely moving rats. During chewing, the amount of saliva and muscle activity were not always parallel, suggesting different centrifugal effects on autonomic and motor functions. When rejectable taste substance was injected into the mouth, a rhythmical muscle activity was induced accompanying vigorous salivation. This behavior also occurred in decerebrate animals, suggesting that the reflex are of this behavior is situated in the lower brainstem. When salivary glands were extirpated, the jaw movement during chewing became irregular and taste sensitivity of the chorda tympani nerve decreased.Though these studies, we conclude that the autonomic and motor oral functions are under control from the higher central nervous system, but there is a contact point between the two functions in the lower brainstem especially the lateral reticular formation. The activity of the pre-motor neurons of the trigeminal motor nucleus should be analyzed and compared with that of the SS neurons. Less