Neuronal connection of the nociceptive and pain-modulating systems, with special reference to peptides and their receptors involved in the systems.

1.向中脑导水管周围灰质投射轴突的NK1免疫反应阳性神经元主要分布在大鼠延髓和脊髓背角的I层、脊髓外侧核以及脊髓的V、X层。观察NK1免疫活性物质在新生儿和成人脊髓中的分布。在大鼠延髓和脊髓背角的I、II层，P物质或CGRP阳性轴突终末有MU阿片受体免疫反应阳性。在大鼠延髓背角的部分三叉神经丘脑神经元内可见强啡肽前免疫反应阳性。在大鼠延髓切片制作的细胞内记录和标记实验中，根据延髓背角II层局部环路神经元的电膜性质和轴突分支模式，将其分为两种类型。其中一类局部环路神经元呈Calbindin D28K免疫反应阳性。在大鼠延髓背角向臂旁、丘脑或下丘脑投射轴突的神经元中，观察到钙结合蛋白(小白蛋白、钙视黄素、钙结合蛋白D28K)的免疫反应阳性。口周皮下注射10%福尔马林后，部分神经元表达c-Fos免疫反应。

1. NK1-immunoreactive neurons sending their axons to the periaqueductal gray were distributed mainly in lamina I of the medullary and spinal dorsal horns, spinal lateral nucleus, and additionally in laminae V and X of the spinal cord in the rat.2. Distribution of NK1-immunoreactivity was examined in the newborn and adult human spinal cords.3. Mu-opioid receptor-immunoreactivity was found in substance P- or CGRP-immunoreactive axon terminals in laminae I and II of the medullary and spinal dorsal horn of the rat.4. Preprodynorphin-immunoreactivity was found in some trigeminothalamic neurons in the medullary dorsal horn of the rat.5. In intracellular recording and labeling experiments in slice preparations of the rat medulla oblongata, local circuit neurons in lamina II of the medullary dorsal horn were divided into two types on the basis of their electrical membrane properties and axonal arborization patterns. A population of the local circuit neurons of one type showed calbindin D28K-immunoreactivity.6. Immunoreactivities for calcium-binding proteins (parvalbumin, calretinin, calbindin D28K) were observed in medullary dorsal horn neurons which send their axons to the parabrachial, thalamic, or hypothalamic regions in the rat. Some of these neurons were confirmed to express c-Fos-immunoreactivity when 10% formalin was injected subcutaneously into the perioral regions.