Transection of the rat olfactory nerve increases glial fibrillary acidic protein immunoreactivity from the olfactory bulb to the piriform cortex.
Transection of the rat olfactory nerve increases glial fibrillary acidic protein immunoreactivity from the olfactory bulb to the piriform cortex.
复制标题
大鼠嗅神经的横断增加了从嗅球到梨状皮层的胶质纤维酸性蛋白免疫反应性。
作者：
Anders,JJ;Johnson,JA
星形胶质细胞纤维酸性蛋白（GFAP）对轴索切除术后运动神经元逆行变化的免疫反应性已成为许多报告的主题。相比之下，这项研究检查了成年大鼠感觉系统（嗅觉系统）中轴索切断术的星形胶质细胞 GFAP 免疫反应性。本研究的目的是通过免疫标记 GFAP 确定嗅觉系统中星形胶质细胞反应的程度和短暂性。在筛板水平颅内进行嗅神经束的单侧横断。轴突切除术后大鼠存活24小时至1个月。使用过氧化物酶-抗过氧化物酶方法检查整个大鼠嗅觉系统的 GFAP 免疫标记。轴索切除术后，同侧嗅觉系统中星形胶质细胞 GFAP 免疫反应性出现短暂增加。嗅觉系统中 GFAP 免疫反应性的最大增强发生在轴突切除术后 48 小时。 GFAP 免疫反应性的增加不仅发生在受损初级嗅觉神经元的轴突和突触末端，而且还发生在次级感觉神经元的树突、细胞体、轴突和突触末端。 GFAP 免疫反应性的增加与初级和次级嗅觉神经元的解剖分布途径特别相关。 GFAP 免疫反应性的增加直到轴突切除后 14 天才发生改变。轴突切除术后 1 个月，GFAP 免疫反应性恢复到对照水平。 GFAP 免疫反应性增加的时间过程和短暂性与轴索切除后大鼠原发性嗅觉神经元变性和再生的时间过程密切相关。沿着次级嗅觉神经元的星形胶质细胞 GFAP 免疫反应性的增加表明存在与初级嗅觉神经元的变性和再生状态直接相关的突触效应的存在。
Astrocytic glial fibrillary acidic protein (GFAP) immunoreactivity in response to retrograde changes of motoneurons after axotomy has been the subject of a number of reports. In contrast, this study examined the astrocytic GFAP immunoreactivity in response to axotomy in a sensory system, the adult rat olfactory system. The purpose of this study was to determine, by immunolabeling GFAP, the extent and transience of astrocytic reactivity in the olfactory system. Unilateral transection of the olfactory nerve fascicles was performed intracranially at the level of the cribriform plate. Rats were allowed to survive from 24 hours to 1 month after axotomy. GFAP immunolabeling was examined throughout the rat olfactory system using the peroxidase–anti‐peroxidase method. After axotomy, a transient increase occurred in the astrocytic GFAP immunore‐activity in the ipsilateral olfactory system. The greatest enhancement of GFAP immuno‐reactivity in the olfactory system occurred at 48 hours post‐axotomy. Increased GFAP immunoreactivity occurred not only along the axons and synaptic endings of the injured primary olfactory neurons, but also along the dendrites, cell bodies, axons, and synaptic endings of the secondary sensory neurons. The increased GFAP immunoreactivity was specifically associated with the anatomical distribution pathways of the primary and secondary olfactory neurons. Increased GFAP immunoreactivity was not altered until 14 days post‐axotomy. At 1 month post‐axotomy, GFAP immunoreactivity returned to control levels. The time course and transience of increased GFAP immunoreativity closely correlates with the time course of rat primary olfactory neuronal degeneration and regeneration after axotomy. The increase in astrocytic GFAP immunoreactivity along the secondary olfactory neurons suggests the existence of a transsynaptic effect that is directly related to the state of degeneration and regeneration of the primary olfactory neurons.