Role of CRP-positive cerebellar climbing fiber system on the development of vestibular compensation : An animal model study.

目前的免疫组织化学研究表明，在共济失调突变体名古屋滚动小鼠（RMN）中，前庭小脑中促肾上腺皮质激素释放因子（CRF）阳性的苔藓和攀爬纤维终端数量增加。单极刷状细胞（ubc）是前庭小脑中的一类中间神经元，可以放大苔藓纤维的兴奋性输入。前庭小脑中calretinin （CR）阳性的ubc数量在RNM和对照组小鼠之间没有差异。但是，在RMN中，靠近cr阳性ubc的cfr阳性苔藓纤维终端的数量是对照组的5倍。提示前庭小脑中与ubc接触的crf阳性苔藓纤维终端补偿RMN小脑共济失调。我们试图阐明前庭小脑中与ubc接触的crf阳性苔藓纤维终端在前庭代偿发展中的作用。小鼠单侧迷路切除后，前庭小脑中与ubc接触的crf阳性苔藓纤维终端数量没有变化。虽然RMN的前庭小脑中crf阳性的攀爬纤维终端数量增加，但单侧迷路切除术后小鼠前庭小脑中crf阳性的攀爬纤维终端数量没有变化。这些结果表明，前庭小脑中crf阳性的苔藓纤维和攀爬纤维在前庭代偿的发展中没有作用。相反，小鼠单侧迷路切除后，同侧前庭内侧核的CRF阳性终末数量减少，提示CRF影响前庭核的前庭代偿发育，而不影响前庭小脑。

Role of CRP-positive cerebellar climbing fiber system in the development of vestibular compensationThe present immunohistochemical study demonstrated an increase in number of corticotropin-releasing factors (CRF)-positive mossy and climbing fiber terminals in the vestibulocerebellum in an ataxic mutant, rolling mouse Nagoya (RMN). Unipolar brush cells (UBCs), a class of interneurons in the vestibulocerebellum, amplifies excitatory inputs from mossy fibers. The number of calretinin (CR)-positive UBCs in the vestibulocerebellum was no different between RNM and the control mice. But, the number of CFR-positive mossy fiber terminals in closely apposition to CR-positive UBCs was 5-fold greater in RMN than in the controls. It is suggested that CRF-positive mossy fiber terminals in contact with UBCs in the vestibulocerebellum compensate the cerebellar ataxia in RMN.An attempt was made to clarify the roles of CRF-positive mossy fiber terminals in contact with UBCs in the vestibulocerebellum in the development of vestibular compensation. After unilateral labyrinthectomy in mice, there were no changes in number of CRF-positive mossy fiber terminals in contact with UBCs in the vestibulocerebellum. Although the number of CRF-positive climbing fiber terminals was increased in the vestibulocerebellum of RMN, there were no changes in number of CRF-positive climbing fiber terminals in the vestibulocerebellum after unilateral labyrinthectomy in mice. All these findings suggest that CRF-positive mossy and climbing fibers in the vestibulocerebellum do not play roles in the development of vestibular compensation.On the contrary, the number of CRF-positive terminals in the ipsilateral medial vestibular nucleus was decreased after unilateral labyrinthectomy in mice, suggesting that CRF affects the development of vestibular compensation in the vestibular nuclei, but not in the vestibulocerebellum.