Department of Neurobiology, University of Alabama at Birmingham, Birmingham, United States.
Elife. 2017 Oct 13;6:e29215. doi: 10.7554/eLife.29215.
Golgi cells are the principal inhibitory neurons at the input stage of the cerebellum, providing feedforward and feedback inhibition through mossy fiber and parallel fiber synapses. In vivo studies have shown that Golgi cell activity is regulated by climbing fiber stimulation, yet there is little functional or anatomical evidence for synapses between climbing fibers and Golgi cells. Here, we show that glutamate released from climbing fibers activates ionotropic and metabotropic receptors on Golgi cells through spillover-mediated transmission. The interplay of excitatory and inhibitory conductances provides flexible control over Golgi cell spiking, allowing either excitation or a biphasic sequence of excitation and inhibition following single climbing fiber stimulation. Together with prior studies of spillover transmission to molecular layer interneurons, these results reveal that climbing fibers exert control over inhibition at both the input and output layers of the cerebellar cortex.
高尔基细胞是小脑输入阶段的主要抑制性神经元，通过苔藓纤维和平行纤维突触提供前馈和反馈抑制。体内研究表明，高尔基细胞的活动受到 climbing fiber 刺激的调节，但在 climbing fiber 和高尔基细胞之间存在突触的功能或解剖学证据很少。在这里，我们表明，来自 climbing fiber 的谷氨酸通过溢出介导的传递激活高尔基细胞上的离子型和代谢型受体。兴奋性和抑制性电导的相互作用为高尔基细胞的爆发提供了灵活的控制，使得在单个 climbing fiber 刺激后，无论是兴奋还是兴奋和抑制的双相序列都可以发生。与先前关于分子层中间神经元溢出传递的研究一起，这些结果表明，climbing fibers 对小脑皮层的输入和输出层的抑制都具有控制作用。
