大鼠束缚后脑内星形胶质细胞的反应

为了探讨束缚后大鼠脑内星形胶质细胞的反应,本实验将大鼠束缚于小的塑料桶内1、3或6 h,于解束后30 min处死,正常大鼠不被束缚作为对照。脑组织进行抗glial fibrillary acidic-protein(GFAP)免疫组织化学染色。结果显示:在正常大鼠脑内有少数散在静止状态的星形胶质细胞,表现为胞体小、突起细、GFAP淡染,缺乏机能定位分布特点;束缚后脑内星形胶质细胞表现为胞体肥大、突起变粗、GFAP深染、形成激活状态,其分布有明显的机能定位特点,表达于与应激反应调节相关的核团,主要有(1)端脑:扣带回、新皮质(尤其是第Ⅲ和V层)、隔外侧核、杏仁中央核;(2)间脑:丘脑室旁核、外侧膝状体、内侧膝状体、下丘脑的视上核、室旁核、第三脑室室周区、弓状核;(3)脑干:中脑的上丘浅层、中脑导水管周围灰质、下丘的皮质部;脑桥的臂旁外侧核、蓝斑、A5区;延髓的耳蜗核、延髓内脏带(MVZ)等处。反应性星形胶质细胞表达的时程变化是束缚1 h最高,3 h次之,6 h最少。本文结果表明,大鼠被束缚后全脑多处核团的星形胶质细胞发生不同程度的改变,随着束缚时间的延长,动物产生适应性,星形胶质细胞表达减少。

MORPHOLOGICAL RESPONSES OF THE ASTROCYTES IN RAT BRAINS TO RESTRAINT STRESS

To investigate morphological response of the astrocytes in rat brains to restraint stress, the experimental rats were restricted in a small plastic tub for 1, 3 and 6 hours, and were sacrificed at 30 min after removing restraint. The control rats were not restricted. Immunohistochemical ABC methods were used to observe the distribution of glial fibrillary acidic protein (GFAP)-like immunoreactive (-LI) products in rat brain. A few astrocytes were found in normal brain. These cells had small cell bodies, thin processes and light staining with GFAP, and the characteristics of functional distribution were not observed. After restriction, responded astrocytes were found. These cells appeared with the cell hypertrophied bodies, thickened processes and deep staining with GFAP, and the characteristics of functional distribution were clearly observed. GFAP-LI astrocytes appeared mainly in (1) Telencephalon: the cingulum, cortex (especially in the third and fifth layer) , lateral septal nucleus, central amygdaloid nucleus! (2) Diencephalon: the thalamic paraventricular nucleus, lateral geniculate body and medial genicular body, hypothalamic paraventricular nucleus, supraoptic nucleus, periventricular area of the third ventricle, arcuate nucleus; (3) Brain stem: the superficial layer of superior colliculus, periaqueductal gray, cortical area of inferior collieulus, lateral parabrachial nucleus, locus coeruleus, A5 area, cochlear nuclei, medullary visceral zone in medulla oblongata. The expression of GFAP-LI astrocytes peaked at 1 h after restriction, then decreased at 3 h, and reached the lowest at 6 h. The results suggest that the different response levels of GFAP-LI astrocytes in many areas of brain are induced with restraint stress, and rats adapt to restraint stimulation and expression of GFAP-LI astrocytes decreases with prolonged restraint time.