Target-Dependent Feedforward Inhibition Mediated by Short-Term Synaptic Plasticity in the Cerebellum
Target-Dependent Feedforward Inhibition Mediated by Short-Term Synaptic Plasticity in the Cerebellum
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DOI：
10.1523/jneurosci.0276-10.2010
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发表时间：
2010-06-16
影响因子：
5.3
通讯作者：
Sakaba, Takeshi
中科院分区：
文献类型：
--
作者：
Bao, Jin;Reim, Kerstin;Sakaba, Takeshi
小脑前馈抑制（FFI）是由两个不同的途径介导的浦肯野细胞（PC）的不同亚细胞区室。颗粒细胞的轴突，即平行纤维，不仅与PC形成兴奋性突触，还与两种类型的中间神经元（篮状细胞和星状细胞）形成兴奋性突触。然后篮状细胞和星状细胞分别向浦肯野细胞的索马和树突发送抑制信号。然而，体细胞和树突FFI通路之间的功能差异仍然未知。在这里，我们解决这个问题，通过研究如何在小鼠小脑的高频率颗粒细胞输入下动态地招募篮状细胞和星状细胞。FFI回路内各种突触的短期可塑性已被探索。出乎意料的是，当突触后靶点是篮状细胞时，被认为在重复刺激过程中起促进作用的平行纤维突触显示出抑制。FFI回路中的其他因素，如中间神经元的放电特性和抑制性突触的动力学，在体细胞和树突通路之间是相似的。目标依赖的平行纤维突触可塑性的功能后果的两个FFI途径，因为我们观察到，PC接收短暂的体细胞抑制在50 Hz的刺激颗粒细胞，但持久的树突状抑制。
Cerebellar feedforward inhibition (FFI) is mediated by two distinct pathways targeting different subcellular compartments of Purkinje cells (PCs). The axon of the granule cell, the parallel fiber, makes excitatory synapses not only onto PCs but also onto two types of interneurons, basket and stellate cells. Basket and stellate cells then send inhibitory signals to the soma and dendrites of Purkinje cells, respectively. Functional differences between somatic and dendritic FFI pathways, however, remain unknown. Here we address this question by examining how basket and stellate cells are recruited dynamically under high-frequency granule cell inputs at mice cerebellum. Short-term plasticity of various synapses within the FFI circuit has been explored. Unexpectedly, the parallel fiber synapse, which was considered to be facilitating during repetitive stimulation, shows depression, when the postsynaptic target is a basket cell. Other factors in the FFI circuit, such as firing properties of interneurons and dynamics of inhibitory synapses, are similar between somatic and dendritic pathways. The target-dependent parallel fiber synaptic plasticity has functional consequences for the two FFI pathways, because we observe that PCs receive transient somatic inhibition during 50 Hz stimulation of granule cells but persistent dendritic inhibition.