Kar S, Quirion R
Douglas Hospital Research Centre, McGill University, Verdun, Quebec, Canada.
Eur J Neurosci. 1994 Dec 1;6(12):1917-21. doi: 10.1111/j.1460-9568.1994.tb00583.x.
The discrete distribution and possible changes in specific [125I]galanin binding sites were evaluated in the rat spinal cord following neonatal capsaicin treatment, dorsal rhizotomy and sciatic nerve section. The highest density of [125I]galanin binding sites in the normal rat spinal cord was particularly evident in the superficial layers of the dorsal horn whereas moderate to low amounts of labelling were associated with the deeper dorsal horn, areas around the central canal and the ventral horn. Capsaicin-treated rats, compared to littermate controls, showed a significant bilateral increase in [125]galanin binding in the superficial laminae of the dorsal horn. Similarly, unilateral dorsal rhizotomy evoked a significant increase in the density of [125l]galanin binding sites in the superficial dorsal horn ipsilateral to surgery. Section of the sciatic nerve, on the other hand, induced a significant depletion in [125l]galanin binding in laminae I and II of the ipsilateral dorsal horn. These results, in parallel to those reported for galanin immunoreactivity under similar conditions, suggest that [125I]galanin binding sites are preferentially located postsynaptically to the primary afferent fibre terminals in the dorsal horn of the spinal cord. Thus it seems that galanin, at the level of the dorsal spinal cord, regulates the processing of nociceptive information by acting on its own class of specific receptors located postsynaptically to primary sensory terminals.
在新生大鼠经辣椒素处理、背根切断和坐骨神经切断后，评估了大鼠脊髓中特定[125I]甘丙肽结合位点的离散分布及可能的变化。正常大鼠脊髓中[125I]甘丙肽结合位点的最高密度在背角浅层尤为明显，而背角深层、中央管周围区域和腹角的标记量为中等至低水平。与同窝对照相比，经辣椒素处理的大鼠背角浅层[125]甘丙肽结合出现显著的双侧增加。同样，单侧背根切断术使手术同侧背角浅层[125I]甘丙肽结合位点的密度显著增加。另一方面，坐骨神经切断术导致同侧背角I层和II层中[125I]甘丙肽结合显著减少。这些结果与在类似条件下报道的甘丙肽免疫反应性结果一致，表明[125I]甘丙肽结合位点优先位于脊髓背角初级传入纤维终末的突触后。因此，在脊髓背侧水平，甘丙肽似乎通过作用于其自身一类位于初级感觉终末突触后的特异性受体来调节伤害性信息的处理。
