Synaptic inhibition, excitation, and plasticity in neurons of the cerebellar nuclei.
Synaptic inhibition, excitation, and plasticity in neurons of the cerebellar nuclei.
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DOI：
10.1007/s12311-009-0140-6
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发表时间：
2010-03
期刊：
影响因子：
3.5
通讯作者：
Raman, Indira M.
中科院分区：
文献类型：
--
作者：
Zheng, Nan;Raman, Indira M.
关键词：
小脑核的神经元产生小脑的非前庭输出。像其他神经元一样，它们整合兴奋性和抑制性突触输入，并通过其内在特性过滤它们，以产生动作电位输出模式。然而，小脑核细胞的突触和内在特征在几个方面是不寻常的：这些神经元从浦肯野神经元接受大量的基础和驱动抑制，但也是自发活动的，即使没有兴奋也能产生动作电位。此外，不仅核细胞的尖峰对抑制的量敏感，而且抑制的强度也对尖峰的量敏感，通过多种形式的长期可塑性。在这里，我们回顾了突触的兴奋和抑制，其短期的可塑性，其对小脑核神经元的动作电位放电的影响，以及兴奋，抑制和尖峰之间的相互作用，产生长期的变化，突触强度的属性。这些数据提供的证据表明，小脑回路中的电和突触信号是可塑性和弹性的：IPSP和EPSP的强度很容易改变小脑核细胞的活动被修改。然而，值得注意的是，许多已确定的可塑性形式具有明显的稳态效应，通过将小脑输出恢复到扰动前的值来响应输入的扰动。这种形式的自我调节似乎与小脑输出在协调运动中的作用一致。相比之下，核细胞中的其他形式的可塑性，包括兴奋性突触后电流（EPSC）的长时程增强和内在兴奋性的兴奋驱动增加，是非稳态的，相反，似乎适合于将电路带到一个新的设定点。有趣的是，增强EPSC的抑制性和兴奋性刺激的组合类似于预测在眼睑调节期间发生的活动模式，这表明这种形式的长时程增强，可能被内在可塑性放大，可能代表小脑学习期间参与的细胞机制。
Neurons of the cerebellar nuclei generate the non-vestibular output of the cerebellum. Like other neurons, they integrate excitatory and inhibitory synaptic inputs and filter them through their intrinsic properties to produce patterns of action potential output. The synaptic and intrinsic features of cerebellar nuclear cells are unusual in several respects, however: these neurons receive an overwhelming amount of basal and driven inhibition from Purkinje neurons, but are also spontaneously active, producing action potentials even without excitation. Moreover, not only is spiking by nuclear cells sensitive to the amount of inhibition, but the strength of inhibition is also sensitive to the amount of spiking, through multiple forms of long-term plasticity. Here, we review the properties of synaptic excitation and inhibition, their short-term plasticity, and their influence on action potential firing of cerebellar nuclear neurons, as well as the interactions among excitation, inhibition, and spiking that produce long-term changes in synaptic strength. The data provide evidence that electrical and synaptic signaling in the cerebellar circuit is both plastic and resilient: the strength of IPSPs and EPSPs readily changes as the activity of cerebellar nuclear cells is modified. Notably, however, many of the identified forms of plasticity have an apparently homeostatic effect, responding to perturbations of input by restoring cerebellar output toward pre-perturbation values. Such forms of self-regulation appear consistent with the role of cerebellar output in coordinating movements. In contrast, other forms of plasticity in nuclear cells, including a long-term potentiation of excitatory postsynaptic currents (EPSCs) and excitation-driven increases in intrinsic excitability, are non-homeostatic, and instead appear suited to bring the circuit to a new set point. Interestingly, the combinations of inhibitory and excitatory stimuli that potentiate EPSCs resemble patterns of activity predicted to occur during eyelid conditioning, suggesting that this form long-term potentiation, perhaps amplified by intrinsic plasticity, may represent a cellular mechanism that is engaged during cerebellar learning.
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影响因子：
25
作者：
Alvina, Karina;Walter, Joy T.;Kohn, Adam;Ellis-Davies, Graham;Khodakhah, Kamran
通讯作者：
Khodakhah, Kamran
影响因子：
2.5
作者：
Afshari, FS;Ptak, K;Raman, IM
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Raman, IM
影响因子：
2.5
作者：
Aizenman, CD;Linden, DJ
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影响因子：
3.3
作者：
AUDINAT, E;GAHWILER, BH;KNOPFEL, T
通讯作者：
KNOPFEL, T
影响因子：
16.2
作者：
Aizenman, CD;Manis, PB;Linden, DJ
通讯作者：
Linden, DJ