Ladic L A, Buchan A M
Department of Physiology, University of British Columbia, Vancouver, Canada.
J Auton Nerv Syst. 1996 Apr 20;58(1-2):25-34. doi: 10.1016/0165-1838(96)00114-2.
Retrograde tracing and immunocytochemistry were used to identify and map the distribution of substance P (SP) and its receptor (NK-1r) associated with gastric motor neurons in the dorsal motor nucleus of the vagus (DMV) in the rat brain stem. The presence of peptide and receptor in surrounding regions within the dorsal vagal complex were also observed. Injection of the retrograde tracer Fluorogold (FG) into the greater curvature of the stomach produced bilateral labelling of neurons within the DMV. The majority of the NK-1r immunoreactivity appeared as an intricate lattice of fibres with a small number of immunoreactive cell bodies. The NK-1r-labelled fibres were detected within the DMV in close association with FG-labelled neurons and in the region between the DMV and nucleus of the solitary tract (NTS). A proportion of FG-labelled neuronal cell bodies were also labelled with NK-1r (7% of total). The greatest density of NK-1r-labelled fibres was observed at the rostral end of the FG-labelled neuron columns in the DMV (close to the IV ventricle) in the region where gastric vagal afferents terminate. Little NK-1r labelling was observed at the caudal end of the FG-labelled neuron tracts adjacent to the central canal. In the coronal plane, the NK-1r-labelled fibres were seen at the edges of the DMV extending into overlying NTS. Substance P was visualized as a dense network of fibres spanning the entire length of the DMV and in close association with FG-labelled neurons. Substance P staining was also detected in the NTS and in the ventral AP. Most of the association between SP/NK-1r immunoreactive fibres was observed within the DMV and at the border between the DMV and NTS. These findings suggest that SP directly regulates a subpopulation of efferent neurons in the DMV which project to the greater curvature of stomach.
采用逆行示踪和免疫细胞化学方法，对大鼠脑干迷走神经背核（DMV）中与胃运动神经元相关的P物质（SP）及其受体（NK-1r）进行鉴定和定位。同时也观察了迷走神经背侧复合体周围区域中肽和受体的存在情况。将逆行示踪剂荧光金（FG）注入胃大弯，可使DMV内的神经元出现双侧标记。大多数NK-1r免疫反应性表现为错综复杂的纤维网络，伴有少量免疫反应性细胞体。在DMV内检测到NK-1r标记的纤维，它们与FG标记的神经元紧密相连，并存在于DMV与孤束核（NTS）之间的区域。一部分FG标记的神经元胞体也被NK-1r标记（占总数的7%）。在DMV中FG标记的神经元柱的头端（靠近第四脑室），即胃迷走神经传入纤维终止的区域，观察到NK-1r标记纤维的密度最高。在靠近中央管的FG标记神经元束的尾端，几乎没有观察到NK-1r标记。在冠状平面上，NK-1r标记的纤维可见于DMV的边缘并延伸至上覆的NTS。P物质表现为横跨整个DMV长度的密集纤维网络，并与FG标记的神经元紧密相连。在NTS和腹侧AP中也检测到P物质染色。SP/NK-1r免疫反应性纤维之间的大多数关联见于DMV内以及DMV与NTS之间的边界处。这些发现表明，SP直接调节DMV中投射至胃大弯的一部分传出神经元。
