Sandkühler J, Maisch B, Zimmermann M
Neurosci Lett. 1987 May 6;76(2):168-72. doi: 10.1016/0304-3940(87)90710-5.
In anesthetized cats, extracellular recordings were made from lumbar spinal dorsal horn neurons, driven by noxious radiant skin heating. Heat-evoked responses were inhibited during electrical stimulation in the medullary nucleus raphe magnus (NRM). To identify the spinal pathways mediating this descending inhibition, reversible blocks in the spinal cord white matter were produced by microinjection of the local anesthetic lidocaine. Descending inhibition from the NRM was significantly reduced during blocks in the dorsal and medial, but not ventral parts of the contralateral lateral funiculus (LF). Blocks at any site in the ipsilateral LF failed to affect NRM-induced descending inhibition. These results indicate that NRM-induced inhibition of nociceptive dorsal horn neurons is conveyed primarily in fibers descending in the contralateral spinal white matter.
在麻醉猫中，对由伤害性皮肤辐射热刺激驱动的腰段脊髓背角神经元进行细胞外记录。在延髓中缝大核（NRM）进行电刺激期间，热诱发反应受到抑制。为了确定介导这种下行抑制的脊髓通路，通过微量注射局部麻醉药利多卡因在脊髓白质中产生可逆性阻断。在对侧外侧索（LF）的背侧和内侧部分而非腹侧部分进行阻断期间，来自NRM的下行抑制显著降低。同侧LF中任何部位的阻断均未影响NRM诱导的下行抑制。这些结果表明，NRM诱导的对伤害性背角神经元的抑制主要通过对侧脊髓白质中下行的纤维进行传递。
