Zerari-Mailly Fawzia, Buisseret Pierre, Buisseret-Delmas Catherine, Nosjean Anne
Laboratoire de Neuroanatomie Fonctionnelle des Systèmes Sensorimoteurs, 75251 Paris Cedex 05, France.
J Comp Neurol. 2005 Jun 27;487(2):176-89. doi: 10.1002/cne.20554.
This study was undertaken to identify premotor neurons in the nucleus tractus solitarii (NTS) serving as relay neurons between the sensory trigeminal complex (STC) and the facial motor nucleus in rats. Trigemino-solitarii connections were first investigated following injections of anterograde and/or retrograde (biotinylated dextran amine, biocytin, or gold-HRP) tracers in STC or NTS. Trigemino-solitarii neurons were abundant in the ventral and dorsal parts of the STC and of moderate density in its intermediate part. They project throughout the entire rostrocaudal extent of the NTS with a strong lateral preponderance. Solitarii-trigeminal neurons were observed mostly in the rostral and rostrolateral NTS. They mainly project to the ventral and dorsal parts of the spinal trigeminal nucleus but not to the principal nucleus. Additional neurons located in the middle NTS were found to project exclusively to the spinal trigeminal nucleus pars caudalis. No solitarii-trigeminal cells were observed in the caudal NTS. In addition, evidence was obtained of NTS retrogradely labeled neurons contacted by anterogradely labeled trigeminal terminals. Second, solitarii-facial projections were analyzed following injections of anterograde and retrograde tracers into the NTS and the facial nucleus, respectively. NTS neurons, except those of the rostrolateral part, reached the dorsal aspect of the facial nucleus. Finally, simultaneous injections of anterograde tracer in the STC and retrograde tracer in the facial nucleus gave retrogradely labeled neurons in the NTS receiving contacts from anterogradely labeled trigeminal boutons. Thus, the present data demonstrate for the first time the existence of a trigemino-solitarii-facial pathway. This could account for the involvement of the NTS in the control of orofacial motor behaviors.
本研究旨在确定孤束核（NTS）中的运动前神经元，其作为大鼠感觉三叉神经复合体（STC）和面运动核之间的中继神经元。在STC或NTS中注射顺行和/或逆行（生物素化葡聚糖胺、生物胞素或金-辣根过氧化物酶）示踪剂后，首先研究了三叉神经-孤束连接。三叉神经-孤束神经元在STC的腹侧和背侧部分丰富，在其中间部分密度适中。它们投射到NTS的整个 rostrocaudal 范围，且在外侧占优势。孤束-三叉神经元主要见于NTS的吻侧和吻外侧。它们主要投射到三叉神经脊束核的腹侧和背侧部分，而不投射到主核。发现位于NTS中部的其他神经元仅投射到三叉神经脊束核尾侧部。在NTS尾侧未观察到孤束-三叉细胞。此外，还获得了证据，即顺行标记的三叉神经终末与逆行标记的NTS神经元接触。其次，分别向NTS和面神经核注射顺行和逆行示踪剂后，分析了孤束-面神经投射。除吻外侧部分的NTS神经元外，其他NTS神经元到达面神经核的背侧。最后，在STC中同时注射顺行示踪剂，在面神经核中注射逆行示踪剂，结果在NTS中发现了逆行标记的神经元，这些神经元接受顺行标记的三叉神经终扣的接触。因此，本研究数据首次证明了三叉神经-孤束-面神经通路的存在。这可以解释NTS参与对口面部运动行为的控制。
