大鼠脊髓白质后索内P物质受体阳性神经元的形态特征及其联系

本研究应用免疫组织化学方法和免疫荧光组织化学双标技术,观察了大鼠脊髓白质后索内的P物质(SP)受体(SPR)阳性神经元的形态特征及其联系。结果表明,脊髓白质后索内存在SPR阳性神经元,它们的胞体较小,常集中在两侧后索的中线上,呈三角形、圆形和多极形;它们的短树突在胞体周围呈放射状,但向后索表面行走的树突较直,且可达脊髓表面;在激光共聚焦显微镜下可见这些SPR阳性神经元呈NeuN阳性,但GFAP呈阴性;它们的胞体及其突起与SP、谷氨酸脱羧酶(GAD)、脑啡肽(ENK)和5-HT阳性纤维及终末形成紧密接触。上述结果说明脊髓白质后索内存在神经元,且呈SPR阳性;这些SPR阳性神经元的活动可能受到多种来源神经信号的调控。

Morphological features and connections of the substance P receptor immunopositive neurons in the dorsal column white matter of the spinal cord in the rat

In order to observe the morphological features and fiber connections of the substance P (SP) receptor (SPR)-immunoreactive (ir) neurons in the dorsal column white matter of the spinal cord in the rat, immunohistochemical technique and immunofluorescent histochemical double-staining method were used in the present study. There were SPR-ir neurons in the dorsal column white matter of the spinal cord in the rat. These SPR-ir neurons usually concentrated near the midline of the dorsal column white matter and had small cell bodies. The common shapes of the cell bodies of these SPR-ir neurons were triangular, round and multipolar. Around the cell bodies, their dendritic processes were radial, while the dendritic processes which went toward the dorsal surface of the spinal cord were straight forward, some of them even could reach the dorsal surface of the spinal cord. Under the laser scanning conforcal microscope, it was found these SPR-ir neurons showed NeuN immunopositive and GFAP immunonegative reactions and the dendritic processes and their cell bodies of these SPR-ir neurons made close contacts with fibers as well as axon terminals which exhibited SP-, glutamic acid decarboxylase (GAD)-, enkephalin (ENK)-, and serotonin (5-HT)-immunoreactivities. These results suggest that there are neurons in the dorsal column white matter of the spinal cord, some of these neurons show SPR-immunoreactivities. The preseut results also indicate that the activities of these SPR-ir neurons might be regulated by neural signals originated from different parts of the nervous system.