Li Y Q, Wang Z M, Zheng H X, Shi J W
Department of Anatomy, Fourth Military Medical University, Xi'an, People's Republic of China.
Brain Res. 1996 May 6;719(1-2):219-24. doi: 10.1016/0006-8993(96)00071-6.
After trigeminal rhizotomy, some substance P-like immunoreactive (SP-LI) fibers and terminals in the spinal trigeminal caudal subnucleus (Vc), specially in its superficial laminae (laminae I and II), still remained in the rat. Employing a combination of Fluoro-Gold retrograde tracing and immunofluorescence histochemical staining for SP, we found that the main central origins of these SP-LI fibers and terminals were midbrain periaqueductal gray (PAG), nucleus raphe magnus (NRM) and other raphe nuclei, and nucleus reticularis gigantocellularis pars alpha; all of them are important structures of the endogenous pain control system. The present results provided morphological evidence for PAG or NRM stimulation could inhibit neuronal activities in the Vc evoked by orofacial nociceptive stimulation and also suggested that SP might be an important neurotransmitter or neuromodulator for endogenous pain control system.
三叉神经根切断术后，大鼠三叉神经脊束尾侧亚核（Vc），特别是其浅层（I层和II层）中仍残留一些P物质样免疫反应性（SP-LI）纤维和终末。通过结合荧光金逆行追踪和SP免疫荧光组织化学染色，我们发现这些SP-LI纤维和终末的主要中枢起源是中脑导水管周围灰质（PAG）、中缝大核（NRM）和其他中缝核，以及巨细胞网状核α部；它们都是内源性疼痛控制系统的重要结构。目前的结果为PAG或NRM刺激可抑制口面部伤害性刺激诱发的Vc神经元活动提供了形态学证据，也表明SP可能是内源性疼痛控制系统的一种重要神经递质或神经调质。
