The Vestibular Ocular Reflex of the mutant mice deficient in delta 2 Glutamate receptor Subunit after unilateral labyrinthectomy

点击翻译按钮获取中文摘要

Ionotrophic delta-2 subunit of glutamate receptor is specifically expressed only in cerebellar Purkinje cells in the nervous system, and mutant mice deficient in delta 2 proteins have been raised (Kashiwabuchi 1995).These mice did nor exhibit long term depression (LTD), which is one form of synaptic plasticity (Hirano 1995). We examined the postural righting reflex and vestibulo ocular reflex (VOR) after unilateral labyrinthectomy (UL) in these mutant mice, to investigate the involvement of LTD in vestibular compensation. And we also examined the c-Fos expression after unilateral ladyrinthectomy in these mutant mice, to investigate the morphological change during the vestibular compensation.After UL in the knock out mice deficient in delta 2 glutamate receptor subunit, the recovery of the postural righting reflex and VOR are retarded than normal mice, which suggests delta 2 glutamate receptor subunit plays an important role in the process of the vestibnlar compensation. After UL in the knock out mice deficient in delta 2 Glutamate Receptor Subunit, c-fos positive cells are greater in number in the contralateral sides in Mve and SpVe than normal, very few in the contralateral PrH and positive in ipsilesionai IO, contrary to normal mice. We assume that the in the knock-out mice which have dysfunctions in the floccules, the neurons in the vestibular nucleus on the contra latreal side became hyperactive because of the disinhibition from the cerebellum. And in knock out mice lacking control from the cerebellar floccules, c-fos was not activated in PrH on this side.