Transient and widespread astroglial activation in the brain after a striatal 6-OHDA-induced partial lesion of the nigrostriatal system
Transient and widespread astroglial activation in the brain after a striatal 6-OHDA-induced partial lesion of the nigrostriatal system
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DOI：
10.1080/00207450490512696
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发表时间：
2005-01-01
影响因子：
2.2
通讯作者：
Chadi, G
中科院分区：
文献类型：
--
作者：
Gomide, VC;Silveira, GA;Chadi, G
作者先前描述了在单侧纹状体注射小剂量6-羟基多巴胺(6-OHDA)后，同侧黑质纹状体系统和腹侧被盖区星形胶质细胞的激活。本文进一步评估了纹状体6-OHDA诱导黑质纹状体通路点状损毁后几个脑区星形胶质细胞的反应性。成年雄性Wistar大鼠在新纹状体一侧立体定向注射6-OHDA(8mug/4mul)，1~3周后处死。对照组动物只接受了溶剂。用免疫组织化学方法显示多巴胺细胞标志物酪氨酸羟化酶(TH)和星形胶质细胞标志物胶质纤维酸性蛋白(GFAP)。TH免疫反应终末在注射部位附近的纹状体消失，在同侧黑质致密部(SNc)观察到少量确定的多巴胺细胞体的消失。对侧黑质纹状体通路未检测到多巴胺损伤。1周6-OHDA损毁大鼠的新纹状体和同侧黑质内可见星形胶质细胞反应。使用点截取和旋转器的特定体视学工具显示，注射6-OHDA 1周后，在许多前脑区域，如额叶、顶叶和梨状皮质、隔区、新纹状体和黑质，以及穹隆体区，反应性星形胶质细胞的存在增加。星形胶质细胞的激活以细胞体和/或突起的大小增加为特征。星形细胞反应仅见于3周时同侧黑质纹状体通路，同侧隔区和梨状皮质也有轻微激活。注射溶剂的大鼠仅在靠近针道的新纹状体内可见星形细胞反应。纹状体注射6-OHDA后，在许多脑区观察到的短暂的广泛星形胶质反应可能代表了大脑中的一种全局性旁分泌营养反应。
The authors have previously described astroglial activation in the ipsilateral nigrostriatal system and ventral tegmental area following small doses of 6-hydroxydopamine (6-OHDA) injected unilaterally in the striatum. This article further evaluated astroglial reactivity in several brain regions after striatal 6-OHDA-induced punctate lesion in the nigrostriatal pathway. Adult male Wistar rats received a unilateral stereotaxical injection of the 6-OHDA (8 mug/4 mul) in the neostriatum and sacrificed 1 or 3 weeks later. Control animals received only solvent. Immunohistochemistry was employed for visualization of the tyrosine hydroxylase (TH), marker for dopamine cells, and glial fibrillary acidic protein (GFAP), marker for astrocytes. TH immunoreactive terminals disappeared in the striatum close to the injection site and a disappearance of a small number of a defined population of dopamine cell bodies was observed in the ipsilateral pars compacta of the substantia nigra (SNc). No dopamine lesion was detected in the contralateral nigrostriatal pathway. Astroglial reaction was seen close to the lesion in the neostriatum and in the ipsilateral SNc of the 1 week 6-OHDA lesioned rats. Specific stereological tools employing point intercepts and rotator, revealed an increased presence of reactive astrocytes in many forebrain regions like frontal, parietal and piriform cortex, septum, neostriatum and SNc, bilaterally, and also corpus callosum after 1 week of 6-OHDA injection. The astroglial activation was characterized by increases in the size of the cell body and/or processes. Astrocytic reaction was,found only in the ipsilateral nigrostriatal pathway by 3 weeks of 6-OHDA, a slight activation also remaining in the ipsilateral septum and piriform cortex. Astrocytic reaction was seen in the solvent-injected rats only in the neostriatum close to the needle track. The transient widespread astroglial reaction observed in many brain regions following a striatal injection of 6-OHDA may represent a global paracrine trophic response in the brain.