Microlesions of the inferior olive reduce vestibular modulation of Purkinje cell complex and simple spikes in mouse cerebellum.
Microlesions of the inferior olive reduce vestibular modulation of Purkinje cell complex and simple spikes in mouse cerebellum.
复制标题
DOI：
10.1523/jneurosci.1738-11.2011
复制
发表时间：
2011-07-06
期刊：
影响因子：
--
通讯作者：
Yakhnitsa V
中科院分区：
文献类型：
--
作者：
Barmack NH;Yakhnitsa V
小脑浦肯野细胞有两种不同的动作电位：复合棘波（CS）是由起源于对侧下橄榄核的单根攀爬纤维诱发的。简单棘波（SS）通常归因于苔藓纤维-颗粒细胞-浦肯野细胞的平行纤维输入。虽然这一观点被普遍接受，但缺乏实验支持。前庭刺激独立地激活初级传入苔藓纤维和三级传入攀爬纤维，这些纤维投射到悬雍垂-结节（叶8-10）。CS和SS通常在正弦滚转-倾斜期间反相放电。当CS增加时，SS减少。我们通过对前庭攀爬纤维起源的两个下橄榄核（β核和背内侧细胞柱（DMCC））进行电解质微损伤来测试小鼠中这些通路的相对独立性。这减少了前庭攀爬纤维向对侧叶8-10的信号传导，同时留下完整的前庭初级和次级传入苔藓纤维。我们记录从浦肯野细胞和中间神经元在叶8-10，确定与neurobiotin的细胞标记。下橄榄的微损伤增加了对侧叶8-10的SS自发放电，但在前庭刺激期间阻断了它们的调制。前庭诱发的兴奋性小脑中间神经元（颗粒细胞和单极刷状细胞）的放电没有修改橄榄微病变。星状细胞的调制放电，但不是高尔基体细胞减少了橄榄微病变。我们的结论是前庭调制CS和SS依赖于完整的攀爬纤维。前庭调制的SS的情况下，橄榄微病变反映了攀登纤维诱发的星状细胞放电的损失。
Cerebellar Purkinje cells have two distinct action potentials: Complex spikes (CSs) are evoked by single climbing fibers that originate from the contralateral inferior olive. Simple spikes (SSs) are often ascribed to mossy fiber---granule cell---parallel fiber inputs to Purkinje cells. Although generally accepted, this view lacks experimental support. Vestibular stimulation independently activates primary afferent mossy fibers and tertiary afferent climbing fibers that project to theuvula-nodulus (folia 8-10). CSs and SSs normally discharge antiphasically during sinusoidal roll-tilt. When CSs increase, SSs decrease. We tested the relative independence of these pathways in mice by making electrolytic microlesions of the two inferior olivary nuclei from which vestibular climbing fibers originate; the β-nucleus and dorsomedial cell column (DMCC). This reduced vestibular climbing fiber signaling to the contralateral folia 8-10, while leaving intact vestibular primary and secondary afferent mossy fibers. We recorded from Purkinje cells and interneurons in folia 8-10, identified by juxtacellular labeling with neurobiotin. Microlesions of the inferior olive increased the spontaneous discharge of SSs in contralateral folia 8-10, but blocked their modulation during vestibular stimulation. The vestibularly-evoked discharge of excitatory cerebellar interneurons (granule cells and unipolar brush cells) was not modified by olivary microlesions. The modulated discharge of stellate cells, but not Golgi cells was reduced by olivary microlesions. We conclude that vestibular modulation of CSs and SSs depends on intact climbing fibers. The absence of vestibularly-modulated SSs following olivary microlesions reflects the loss of climbing fiber-evoked stellate cell discharge.