大鼠束缚后脑内小胶质细胞的反应

目的　 探讨大鼠束缚后脑内小胶质细胞的反应及其时程变化。 方法　 将大鼠束缚于小的塑料桶内 1,3或 6h ,于解束后 30min被处死 ,脑组织进行抗OX4 2 (小胶质细胞的特异性标记物 )免疫组织化学染色。结果 　正常大鼠脑内的小胶质细胞一般为静息状态 (静息型 ) ,其特点是OX4 2为阴性或浅染 ,在切片上不易发现或细胞形态不清晰。束缚 1h后 ,小胶质细胞为轻度反应 ,OX4 2浅染 ,细胞形态隐约可见 ,仅于下丘脑的视上核、室旁核和弓状核有散在的表达。束缚 3h后 ,小胶质细胞的反应达到高峰 ,由静息状态变为早期反应状态 (早期反应型 ) ,OX4 2深染 ,细胞形态清楚 ,突起上可见到小棘。早期反应型小胶质细胞广泛分布于前脑 :扣带回、新皮质浅层、隔外侧核、海马CA3、齿状回、杏仁中央核 ;间脑 :下丘脑视前区、视上核、室旁核、第三脑室周区、弓状核、丘脑室旁核、外侧膝状体、内侧膝状体 ;脑干 :中脑的上丘视性层、中脑导水管周围灰质、下丘的皮质部 ;脑桥的外侧臂旁核、蓝斑、A5区 ;延髓的延髓内脏带 (MVZ)和三叉神经脊束核等处 ;束缚 6h后 ,小胶质细胞反应减弱 ,OX4 2浅染 ,分布范围减少 ,主要出现于扣带回、隔外侧核、海马、视上核、室旁核、中脑导水管周围灰质、脑桥的臂旁外侧核、蓝斑、延髓的延髓内脏带 (M

Response of the microglias in rat brains to restraint stress

Objective To investigate plastic response of the microglias in rat brains to restraint stress. Methods The experimental rats were restrained in a small plastic tub for 1, 3 and 6 h, and were sacrificed at 30 min after removing restraint. Immunohistochemical ABC methods were used to observe distribution of OX42 (a specific marker for microglias)-like immunoreactive (-LI) products in rats brain. Results In normal rats the microglias appeared the rested status, OX42 staining was negative or light, cell feature was not clear or could not observed. In rats restrained for 1 h, the microglias appeared light response, OX42-LI was light, OX42-LI cells were found but its feature was not clear. OX42-LI cells only scattered in the hypothalamic paraventricular nucleus, supraoptic nucleus, periventricular area of third ventricle, arcuate nuclrus. In rats restrained for 3 h, the response of microglias peaked, OX42-LI became intense, the feature of cells was clear, spines on processes were clearly found. The early reactive microglias were located in (1) Frontal brain: the cingulum, cortex (specific superficial layer), lateral septal nucleus, hippocampal CA3 area and dentat gyrus, central amygdaloid nucleus. (2) Diencephalon: the hypothalamic paraventricular nucleus, supraoptic nucleus, periventricular area of third ventricle, arcuate nucleus; the thalamic paraventricular nucleus, lateral geniculate body and medial genicular body. (3) Brain stem: the superficial layer of superior colliculus, periaqueductal gray, cortical area of inferior colliculus, lateral parabrachial nucleus, locus coeruleus, A5 area, cochlear nuclei, medullary viceral zone (MVZ) in medulla oblongata. In the rats restrained for 6 h, the response of microglias decreased, OX42-LI became light again, and mainly located in the cingulum, lateral septal nucleus, hippocampus, the hypothalamic paraventricular nucleus, supraoptic nucleus, periaqueductal gray, lateral parabrachial nucleus, locus coeruleus and MVZ. Conclusion The microglias in many areas of brain, which was involved in stress response, from rested state became early activated state. The time course of response was that the response of microglias peaked in rats restrained for 3 h, following for 6 h, 1 h was least.