Local changes in the excitability of the cerebellar cortex produce spatially restricted changes in complex spike synchrony.
Local changes in the excitability of the cerebellar cortex produce spatially restricted changes in complex spike synchrony.
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DOI：
10.1523/jneurosci.3498-09.2009
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发表时间：
2009-11-11
期刊：
影响因子：
--
通讯作者：
Lang EJ
中科院分区：
文献类型：
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作者：
Marshall SP;Lang EJ
复合锋电位（CS）同步模式由下橄榄（IO）内GABA的释放调制。大部分IO的GABA能投射来自小脑核，小脑核本身受到上覆皮层中的浦肯野细胞的强烈抑制控制。此外，IO和小脑之间的连接是精确对齐的，提高了每个皮层区域控制其自己的CS同步分布的可能性。这种可能性进行了测试，使用多电极记录的CS和简单的棘波（SS）在麻醉大鼠的大脑皮层2a。将印防己毒素或蝇蕈醇应用于记录阵列边缘的小脑皮质。这些药物引起CS同步性和CS和SS放电率的显着变化，以及CS后停顿和SS活动调制的变化。对照组的CS同步性水平与SS放电频率相关，印防己毒素的应用增加了两者。相反，蝇蕈醇降低CS同步性。此外，当印防己毒素仅应用于阵列的外侧边缘时，CS同步性的变化在整个记录阵列中依次发生，位于阵列的外侧半部分的细胞比内侧半部分的细胞具有更早和更大的CS同步性变化。结果表明，从浦肯野细胞到IO的双抑制反馈回路提供了一种机制，SS活动可以调节CS同步。因此，CS同步可能是小脑活动的生理控制参数，小脑和IO包括一系列自我更新电路。
Complex spike (CS) synchrony patterns are modulated by the release of GABA within the inferior olive (IO). The GABAergic projection to most of the IO arises from the cerebellar nuclei, which are themselves subject to strong inhibitory control by Purkinje cells in the overlying cortex. Moreover, the connections between the IO and cerebellum are precisely aligned, raising the possibility that each cortical region controls its own CS synchrony distribution. This possibility was tested using multielectrode recordings of CSs and simple spikes (SSs) in crus 2a of anesthetized rats. Picrotoxin or muscimol was applied to the cerebellar cortex at the borders of the recording array. These drugs induced significant changes in CS synchrony and in CS and SS firing rates, and changes in post-CS pauses and modulation of SS activity. The level of CS synchrony was correlated with SS firing rate in control, and application of picrotoxin increased both. In contrast, muscimol decreased CS synchrony. Furthermore, when picrotoxin was applied only at the lateral edge of the array, changes in CS synchrony occurred sequentially across the recording array, with cells located in the lateral half of the array having earlier and larger changes in CS synchrony than cells in the medial half. The results indicate that a double-inhibitory feedback circuit from Purkinje cells to the IO provides a mechanism by which SS activity may regulate CS synchrony. Thus, CS synchrony may be a physiologically controlled parameter of cerebellar activity, with the cerebellum and IO comprising a series of self-updating circuits.