Encoding network states by striatal cell assemblies
Encoding network states by striatal cell assemblies
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DOI：
10.1152/jn.01131.2007
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发表时间：
2008-03-01
影响因子：
2.5
通讯作者：
Bargas, Jose
中科院分区：
文献类型：
--
作者：
Carrillo-Reid, Luis;Tecuapetla, Fatuel;Bargas, Jose
皮质-基底神经节回路中的相关活动在运动编码、联想学习和程序记忆中起着关键作用。纹状体微回路如何组装相关活动尚不清楚。纹状体神经元群体的钙成像，单细胞分辨率，显示在控制条件下的零星和异步活动。然而，N-甲基-D-天冬氨酸（NMDA）的应用诱导纹状体神经元的双稳态和相关活动。观察视野内广泛的神经元呈现爆发性放电。神经元组表现出周期性和同步爆发的事件。网络动力学的简化揭示了由细胞组装定义的功能状态，这些细胞组装交替其活动并显示时空模式生成。经常性的同步活动从一个细胞集合体转移到另一个细胞集合体，通常返回到原始集合体;这表明了一个强大的结构。对维持神经元组装相关活动的因素的初步研究表明，对内在机制和突触机制的关键依赖性：阻断快速GABA能传递会消除所有相关的放电，而阻断GABA能传递会将网络锁定在一个单一的主导状态，从而消除组装多样性。L型Ca 2+电流的减少抑制同步化。每个细胞集合体由不同的细胞组成，但不同的集合体共享一小部分神经元。很大一部分共享神经元是具有起搏特性的局部中间神经元。在纹状体网络中由NMDA启动的网络动力学可以揭示正常和病理条件下纹状体微电路的重要特性。
Correlated activity in cortico-basal ganglia circuits plays a key role in the encoding of movement, associative learning and procedural memory. How correlated activity is assembled by striatal microcircuits is not understood. Calcium imaging of striatal neuronal populations, with single-cell resolution, reveals sporadic and asynchronous activity under control conditions. However, N-methyl-D-aspartate (NMDA) application induces bistability and correlated activity in striatal neurons. Widespread neurons within the field of observation present burst firing. Sets of neurons exhibit episodes of recurrent and synchronized bursting. Dimensionality reduction of network dynamics reveals functional states defined by cell assemblies that alternate their activity and display spatiotemporal pattern generation. Recurrent synchronous activity travels from one cell assembly to the other often returning to the original assembly; suggesting a robust structure. An initial search into the factors that sustain correlated activity of neuronal assemblies showed a critical dependence on both intrinsic and synaptic mechanisms: blockage of fast glutamatergic transmission annihilates all correlated firing, whereas blockage of GABAergic transmission locked the network into a single dominant state that eliminates assembly diversity. Reduction of L-type Ca2+ current restrains synchronization. Each cell assembly comprised different cells, but a small set of neurons was shared by different assemblies. A great proportion of the shared neurons was local interneurons with pacemaking properties. The network dynamics set into action by NMDA in the striatal network may reveal important properties of striatal microcircuits under normal and pathological conditions.