Faunes Macarena, Oñate-Ponce Alejandro, Fernández-Collemann Sara, Henny Pablo
Laboratorio de Neuroanatomía, Departamento de Anatomía Normal, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile.
Centro Interdisciplinario de Neurociencias, Pontificia Universidad Católica de Chile, Santiago, Chile.
J Comp Neurol. 2016 Mar 1;524(4):738-58. doi: 10.1002/cne.23862. Epub 2015 Oct 8.
Neurons in the trigeminal (Mo5), facial (Mo7), ambiguus (Amb), and hypoglossal (Mo12) motor nuclei innervate jaw, facial, pharynx/larynx/esophagus, and tongue muscles, respectively. They are essential for movements subserving feeding, exploration of the environment, and social communication. These neurons are largely controlled by sensory afferents and premotor neurons of the reticular formation, where central pattern generator circuits controlling orofacial movements are located. To provide a description of the orofacial nuclei of the adult mouse and to ascertain the influence of excitatory and inhibitory afferents upon them, we used stereology to estimate the number of motoneurons as well as of varicosities immunopositive for glutamate (VGluT1+, VGluT2+) and GABA/glycine (known as VIAAT+ or VGAT+) vesicular transporters in the Mo5, Mo7, Amb, and Mo12. Mo5, Mo7, Amb, and Mo12 contain ∼1,000, ∼3,000, ∼600, and ∼1,700 cells, respectively. VGluT1+, VGluT2+, and VIAAT+ varicosities respectively represent: 28%, 41%, and 31% in Mo5; 2%, 49%, and 49% in Mo7; 12%, 42%, and 46% in Amb; and 4%, 54%, and 42% in Mo12. The Mo5 jaw-closing subdivision shows the highest VGluT1+ innervation. Noticeably, the VGluT2+ and VIAAT+ varicosity density in Mo7 is 5-fold higher than in Mo5 and 10-fold higher than in Amb and Mo12. The high density of terminals in Mo7 likely reflects the convergence and integration of numerous inputs to motoneurons subserving the wide range of complex behaviors to which this nucleus contributes. Also, somatic versus neuropil location of varicosities suggests that most of these afferents are integrated in the dendritic trees of Mo7 neurons.
三叉神经（Mo5）、面神经（Mo7）、疑核（Amb）和舌下神经（Mo12）运动核中的神经元分别支配颌骨、面部、咽/喉/食管和舌肌。它们对于进食、环境探索和社交交流所必需的运动至关重要。这些神经元在很大程度上受网状结构的感觉传入神经和运动前神经元控制，控制口面部运动的中枢模式发生器回路就位于网状结构中。为了描述成年小鼠的口面部核，并确定兴奋性和抑制性传入神经对它们的影响，我们使用体视学方法估计了Mo5、Mo7、Amb和Mo12中运动神经元的数量，以及对谷氨酸（VGluT1+、VGluT2+）和GABA/甘氨酸（称为VIAAT+或VGAT+）囊泡转运体免疫阳性的曲张体数量。Mo5、Mo7、Amb和Mo12分别包含约1000、约3000、约600和约1700个细胞。VGluT1+、VGluT2+和VIAAT+曲张体分别占：Mo5中的28%、41%和31%；Mo7中的2%、49%和49%；Amb中的12%、42%和46%；Mo12中的4%、54%和42%。Mo5的闭口亚区显示出最高的VGluT1+神经支配。值得注意的是，Mo7中VGluT2+和VIAAT+曲张体密度比Mo5高5倍，比Amb和Mo12高10倍。Mo7中终末的高密度可能反映了众多输入汇聚并整合到该核所参与的广泛复杂行为的运动神经元中。此外，曲张体在胞体与神经毡中的位置表明，这些传入神经大多整合在Mo7神经元的树突中。
