Morphological and functional studies on NO producing neurons in the brainstem involved in pral sensori-motor functions

nadph - diaphase （NADPH-d）组织化学染色显示大鼠下脑干有明显的神经组。NADPH-d染色显示三叉脊髓背内侧口核（Vo）和前外侧孤立束核（Sn）存在高尔基样网络。另一神经组在三叉神经旁核（paraV）、三叉神经内插核（Vi）与尾核（Vc）间隙区、Vc浅区染色，Vc大细胞区染色较少。在Vo和Sn中，nadph -d阳性神经元的分布与支配口腔内结构的神经经神经节标记的WGA-HRP的中央终端区大部分重叠。nadph -d阳性神经元分布于口内和口外结构的中枢终端区。切断支配口内结构的神经后1 ~ 2周，Vo/Sn标记神经元数量减少。这些结果表明，nadph -d阳性的下脑干神经元可通过口内结构的初级传入神经经突触调节。胚胎第12天（EI2），未对脑内神经元进行NADPH-d染色，对血管进行了染色。在E15，标记神经元出现在Vo和Sn中。出生后第4天（P4）， Vc的大细胞区出现标记。P10在paraV和Vc浅表区出现标记。每个细胞核首次表达NADPH-d后，标记增加或维持到成年期。在Vo和Sn中很早就出现NADPH-d标记，这早于脑干其他部位出现NADPH-d，表明一氧化氮/环鸟苷单磷酸系统在原始口面部感觉运动反射功能中起重要作用。

NADPH-diaphorase (NADPH-d) histochemical staining demonstrated a distinct neural group in the lower brainstem of rats. The NADPH-d stain revealed a Golgi-like network in the dorsomedial spinal trigeminal nucleus oralis (Vo) and rostrolateral solitary tract nucleus (Sn). Another neural group was stained in the paratrigeminal nucleus (paraV), gap region between spinal trigerninal nuclei interpolaris (Vi) and caudalis (Vc), superficial zone of Vc, and much less in the magnocellular zone of Vc. The distribution of NADPH-d-positive neurons in Vo and Sn overlapped mostly with the central terminal area labeled transganglionically with WGA-HRP from nerves innervating the intraoral structures. The distribution of NADPH-d-posibve neurons in Vi and Vc overlapped with the central terminal area from nerves innervating intra- and extra-oral structures. The number of labeled neurons in Vo/Sn decreased one to two weeks after transection of nerves innervating intraoral structures. These results show that NADPH-d-positive neurons in the lower brainstem could be regulated trans-synaptically by primary afferents from the intraoral structures. On embryonic day 12 (EI2), no neurons in the brain were stained for NADPH-d, while blood vessels were stained. On E15, labeled neurons appeared in Vo and Sn. On postnatal day 4 (P4), labeling appeared in the magnocellular zone of Vc. On P10, labeling appeared in paraV and the superficial zone of Vc. After the first expression of NADPH-d in each nuclei, the labeling increased or maintained to the adulthood. The very early appearance of NADPH-d labeling in Vo and Sn, which precedes the appearance of NADPH-d elsewhere in the brainstem, suggests that the nitric oxide/cyclic guanosine monophosphate system has an important role for primitive orofacial sensorimotor reflexive functions.