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Effects or hypergravity on genes expressed in the rat inner car

超重力对大鼠内车基因表达的影响

基本信息

批准号：
13671778
负责人：
DOI Katsumi
金额：
$ 2.3万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2002
项目状态：
已结题

项目摘要

Recovery from balance disorders aster spaceflight is supposed.to reflect the readaptation to normal gravitational environment (1G). from microgravity, In the present study, to elucidate a role of otoconia in adaptation to altered gravity, we examined the effects of hypergravity (2G) on nor polo and synthesis of otoconia in young adult rats, Neither otoconial morphology nor otoconial synthesis was affected by up to 1 week exposure to hypergravity, These results suggest that changes in neurotransmission at the synapses or flit peripheral and/or contral vestibular system rather than the Changes in otoconial morphology and synthesis may be involved in adaptive mechanismsWe also assessed the changes in mRNA expression of glutamate receptors in the vestibular system of rats exposed to hypergravily for 2 h to 1 week using real-time quantitative RT-PCR, Tho expression of GluR2 and NRI in khe uvula/nodulus and NR1 in the medial vestibuiar nucleus increased after 2 h of hypergravity, The expresion of GluR2 in vestibular ganglion cells decreased after 1 week of hypergravity ; The results suggested that the animals adapted to the hypergravity by enhancing the crrebellar inhibition of the vestibular nucleus via an activation of the NR1 and GluR2 on tha Purkinje cells in uvula/nodules especially of the early phase following hypergravity, while in the later phase by reducing the neurotransmission between the vestibular hair cells and the primary vestibular neurons via down-regulation of the postsynaptic GluR2 in the vestibular periphery

从平衡障碍中恢复应该是在太空飞行，以反映对正常重力环境(1G)的重新适应。本研究从微重力的角度，研究了超重力(2G)对幼年大鼠耳石形态和耳锥合成的影响。结果表明，超重力暴露2~1周后，耳锥形态和耳锥合成均无明显变化，提示突触或耳廓周围和(或)前庭神经传递的改变，而不是耳锥形态和合成的改变可能参与了适应机制。我们还用实时定量RT-PCR方法检测了超重力暴露2 h至1周大鼠前庭系统谷氨酸受体基因表达的变化。GluR2和NRI在悬垂/结节和NR1在前庭内侧核的表达在超重后2 h增加，在前庭神经节细胞中的表达在超重1周后降低；结果提示，动物对超重力的适应是通过激活悬垂/小结的浦肯野细胞上的NR1和GluR2来增强对前庭神经核的抑制，特别是在超重后的早期，而在超重后期通过下调前庭外周突触后的GluR2来减少前庭毛细胞和初级前庭神经元之间的神经传递。