Bao J, Reier P J, Munson J B
Department of Neuroscience, University of Florida, Gainesville 32610.
Exp Neurol. 1993 Aug;122(2):189-95. doi: 10.1006/exnr.1993.1119.
c-fos immunocytochemistry was used to test a functional correlate of neuroplasticity involving nociceptive primary afferent fibers in the partially denervated adult rat spinal cord. Unilateral dorsal root ganglionectomies were made at L1-L4 (chronic side). After 3 weeks, contralateral L1-L4 ganglionectomies (acute side) were made 1 week prior to sacrifice. Two hours prior to perfusion, the animals were anesthetized and their hindlimbs were immersed in a 52 degrees C water bath for 20 s. The spinal cords were then processed for c-fos immunocytochemistry and the numbers of c-fos-immunoreactive cells determined. Following bilateral noxious thermal stimulation of the hindlimbs, the numbers of c-fos-immunoreactive cells in laminae I-II from L3 to L5 were increased by nearly twofold on the chronically deafferented side of the spinal cord (P < 0.05). This finding suggests augmented functional plasticity of nociceptive primary afferent fibers on the chronically denervated side of spinal cord. These observations are discussed with relation to recent demonstrations of enhanced calcitonin gene-related peptide immunoreactivity and possible primary afferent fiber sprouting in similar denervation models.
采用c-fos免疫细胞化学方法，检测成年部分去神经大鼠脊髓中涉及伤害性初级传入纤维的神经可塑性功能相关性。在L1-L4水平进行单侧背根神经节切除术（慢性侧）。3周后，在处死前1周进行对侧L1-L4神经节切除术（急性侧）。在灌注前2小时，将动物麻醉，并将其后肢浸入52℃水浴中20秒。然后对脊髓进行c-fos免疫细胞化学处理，并确定c-fos免疫反应性细胞的数量。在对后肢进行双侧伤害性热刺激后，脊髓慢性去传入侧L3至L5层中c-fos免疫反应性细胞的数量增加了近两倍（P<0.05）。这一发现表明，脊髓慢性去传入侧伤害性初级传入纤维的功能可塑性增强。结合最近在类似去神经模型中降钙素基因相关肽免疫反应性增强和可能的初级传入纤维发芽的研究结果，对这些观察结果进行了讨论。
