Klein C M, Sorkin L S, Chung K, Coggeshall R E
Department of Anatomy and Neurosciences, University of Texas Medical Branch, Galveston 77550.
Brain Res. 1991 Dec 6;566(1-2):70-6. doi: 10.1016/0006-8993(91)91682-q.
The present study demonstrates many dynorphin (DYN)-immunoreactive fibers and presumed presynaptic terminals in rat lumbar ventral horn. The fibers and terminals seem to arise largely from DYN-containing intrinsic neurons in the dorsal horn. The majority of the presumed terminals closely surround a subpopulation of motoneurons that tend to be located in flexor motoneuron columns. Acute C fiber, but not A fiber, primary afferent stimulation depletes the ventral horn DYN immunostaining. We interpret these findings to indicate that the spinal DYN neurons are well positioned to serve both as modulators of nociceptive input and as interneurons in motor reflexes. We further hypothesize that the depletion of DYN-immunoreactivity that follows either acute C fiber stimulation or intense nociceptive stimuli may be the trigger for the upregulation in spinal cord DYN that occurs in models of chronic pain states.
本研究表明，在大鼠腰段脊髓腹角有许多强啡肽（DYN）免疫反应性纤维及推测的突触前终末。这些纤维和终末似乎主要起源于背角含DYN的内在神经元。大多数推测的终末紧密围绕着一群运动神经元，这些运动神经元往往位于屈肌运动神经元柱内。急性C纤维而非A纤维初级传入刺激可使腹角DYN免疫染色减少。我们将这些发现解释为表明脊髓DYN神经元既能很好地作为伤害性传入的调节因子，又能作为运动反射中的中间神经元。我们进一步推测，急性C纤维刺激或强烈伤害性刺激后DYN免疫反应性的减少可能是慢性疼痛状态模型中脊髓DYN上调的触发因素。
