Bury S D, Eichhorn A C, Kotzer C M, Jones T A
Psychology Department, University of Washington, Guthrie Hall Box 351525, Seattle 98195, USA.
Neuropharmacology. 2000 Mar 3;39(5):743-55. doi: 10.1016/s0028-3908(99)00272-5.
Recent research has suggested that mild denervation of the neocortex of adult rats may facilitate neuronal growth in response to behavioral changes. Astrocytes react to denervation, produce growth-promoting factors and are a potential mediator of this denervation-facilitated growth. The present study assessed whether astrocytic reactions to denervation vary dependent upon post-injury behavioral experience. Denervation of the transcallosal afferents to the motor cortex was induced via partial transections of the corpus callosum. Transected- or sham-operated rats were then either forced to use the opposite forelimb (via limb-restricting vests) or permitted to use both forelimbs normally for 8 days. In the motor cortex, the surface density of glial fibrillary acidic protein (GFAP)-immunoreactive (IR) astrocytic processes and the density of basic fibroblast growth factor (FGF-2)-IR glial cells was significantly increased as a result of transections alone and as a result of forced forelimb-use alone in comparison to controls. The combination of transections and forced-use significantly enhanced GFAP-IR in comparison to all other groups, but did not further enhance FGF-2-IR. These findings are consistent with behavior and denervation having interactive influences on astrocytic reactivity in the motor cortex. These results also raise the possibility that astrocyte-mediated support of neural restructuring after brain injury might be enhanced with appropriate post-injury behavioral manipulations.
最近的研究表明，成年大鼠新皮质的轻度去神经支配可能会促进神经元生长以应对行为变化。星形胶质细胞对去神经支配产生反应，产生生长促进因子，并且是这种去神经支配促进生长的潜在介导者。本研究评估了星形胶质细胞对去神经支配的反应是否因损伤后的行为经验而异。通过胼胝体部分横断诱导运动皮质的胼胝体传入纤维去神经支配。然后，将横断或假手术的大鼠要么被迫使用对侧前肢（通过肢体限制背心），要么允许正常使用两只前肢8天。在运动皮质中，与对照组相比，单独横断以及单独强迫使用前肢均导致胶质纤维酸性蛋白（GFAP）免疫反应性（IR）星形胶质细胞突起的表面密度和碱性成纤维细胞生长因子（FGF-2）-IR胶质细胞的密度显著增加。与所有其他组相比，横断和强迫使用的组合显著增强了GFAP-IR，但没有进一步增强FGF-2-IR。这些发现与行为和去神经支配对运动皮质星形胶质细胞反应性具有交互影响一致。这些结果还提出了一种可能性，即通过适当的损伤后行为操作，脑损伤后星形胶质细胞介导的神经重组支持可能会增强。
