Sharkey K A, Sobrino J A, Cervero F
Department of Physiology, University of Bristol, Medical School, University Walk, U.K.
Neuroscience. 1987 Sep;22(3):1077-83. doi: 10.1016/0306-4522(87)92982-4.
A visceral afferent origin of substance P-like immunoreactivity in lamina V of the lower thoracic spinal cord of the rat was investigated. In transverse sections from normal animals there was a moderately dense substance P-immunoreactive innervation of lamina V. In some sections there was a dorsoventrally orientated fibre bundle from the superficial dorsal horn entering lamina V. In parasagittal sections, substance P-immunoreactivity in lamina V was found arranged in clusters, with a periodicity in the rostrocaudal axis of 200-600 microns. In some cases these were seen to be continuous with a dorsoventrally orientated fibre bundle from the superficial dorsal horn. After section of the splanchnic nerve there was a consistent reduction in the density of the substance P-like immunoreactivity in lamina V, with fewer clusters on the operated side. Adult rats treated neonatally with capsaicin showed a substantial reduction of substance P-immunoreactivity in laminae I and II and the virtual abolition of staining in lamina V. These results provide evidence of a visceral origin for some of the substance P-like immunoreactivity in lamina V of the rat thoracic spinal cord. In addition, they confirm that most of the substance P-immunoreactivity in the dorsal horn is of primary afferent origin.
对大鼠胸段脊髓下部第V层中P物质样免疫反应性的内脏传入起源进行了研究。在正常动物的横切面上，第V层有中等密度的P物质免疫反应性神经支配。在一些切片中，有一束从浅表背角向腹背方向走行的纤维束进入第V层。在矢状旁切面上，发现第V层中的P物质免疫反应性呈簇状排列，在前后轴上的周期为200 - 600微米。在某些情况下，这些簇状结构被观察到与一束从浅表背角向腹背方向走行的纤维束相连。切断内脏神经后，第V层中P物质样免疫反应性的密度持续降低，手术侧的簇状结构减少。新生期用辣椒素处理的成年大鼠，第I层和第II层中的P物质免疫反应性显著降低，第V层中的染色几乎消失。这些结果为大鼠胸段脊髓第V层中一些P物质样免疫反应性的内脏起源提供了证据。此外，它们证实了背角中大多数P物质免疫反应性来自初级传入神经。
