Mahon S, Deniau J M, Charpier S
Institut des Neurosciences, Département de Neurochimie-Anatomie, CNRS UMR 7624, Université Pierre et Marie Curie, 9 quai Saint-Bernard, F-75005 Paris, France.
Cereb Cortex. 2001 Apr;11(4):360-73. doi: 10.1093/cercor/11.4.360.
The functions of the basal ganglia are achieved through excitation of striatal output neurons (SONs) by converging cortical glutamergic afferents. We assessed the relationship between different patterns of activity in cortico-striatal (C-S) cells and the electrical behavior of SONs in vivo. Intracellular activities of rat C-S neurons in the orofacial motor cortex and of SONs, located in the projection field of this cortical region, were recorded under different anesthetics, which generate various temporal patterns of cortical activity. A surface electroencephalogram (EEG) of the orofacial motor cortex was simultaneously performed with intracellular recordings and EEG waves were used as correlates of a coherent synaptic activity in cortical neurons. Under barbiturate anesthesia C-S neurons showed rhythmic (5--7 Hz) supra-threshold depolarizations in phase with large amplitude EEG waves. The correlative activity of SONs was characterized by large amplitude oscillation-like synaptic depolarizations that could trigger action potentials. Under ketamine-xylazine anesthesia C-S neurons exhibited a step-like behavior consisting of depolarizing plateaus (up states), leading to multiple spike discharges, interrupted by hyperpolarizing periods (down states). The related activity of SONs was step-like membrane potential fluctuations with firing confined to the early part of the striatal up state. In C-S neurons and SONs up states coincided with slow recurrent EEG waves (approximately 1 Hz). Finally, under neurolept-analgesia an apparently disorganized EEG activity was associated with a lack of rhythmic discharge in C-S neurons. This uncorrelated activity in C-S neurons resulted in an absence of spontaneous firing as well as of large amplitude synaptic depolarizations in SONs. In the present study we demonstrate that SONs shape their input-output relationship by filtering out uncorrelated synaptic activity and that a minimal synchronization in the cortico-striatal afferents is required to produce significant synaptic depolarization in SONs.
基底神经节的功能是通过汇聚的皮质谷氨酸能传入纤维对纹状体输出神经元（SONs）的兴奋来实现的。我们评估了皮质 - 纹状体（C - S）细胞不同活动模式与体内SONs电行为之间的关系。在不同麻醉剂作用下，记录大鼠口面部运动皮层中C - S神经元以及位于该皮质区域投射场中的SONs的细胞内活动，这些麻醉剂会产生不同的皮质活动时间模式。在进行细胞内记录的同时，同步记录口面部运动皮层的表面脑电图（EEG），并将EEG波用作皮质神经元相干突触活动的相关指标。在巴比妥类麻醉下，C - S神经元表现出与大幅度EEG波同相位的节律性（5 - 7Hz）阈上 depolarizations。SONs的相关活动表现为大幅度的振荡样突触depolarizations，可触发动作电位。在氯胺酮 - 赛拉嗪麻醉下，C - S神经元表现出一种阶梯状行为，由去极化平台期（上行状态）组成，导致多次动作电位发放，期间被超极化期（下行状态）打断。SONs的相关活动是阶梯状的膜电位波动，放电局限于纹状体上行状态的早期。在C - S神经元和SONs中，上行状态与缓慢的递归EEG波（约1Hz）一致。最后，在神经安定镇痛下，明显紊乱的EEG活动与C - S神经元缺乏节律性放电相关。C - S神经元中的这种不相关活动导致SONs中缺乏自发放电以及大幅度的突触depolarizations。在本研究中，我们证明SONs通过滤除不相关的突触活动来塑造其输入 - 输出关系，并且皮质 - 纹状体传入纤维中需要最小程度的同步才能在SONs中产生显著的突触depolarization。 （注：原文中部分单词拼写错误或不完整，如“depolarizations”未完整给出，已按正确内容翻译，但可能会影响对整体准确含义的理解。）
