Inverted-U profile of dopamine-NMDA-mediated spontaneous avalanche recurrence in superficial layers of rat prefrontal cortex
Inverted-U profile of dopamine-NMDA-mediated spontaneous avalanche recurrence in superficial layers of rat prefrontal cortex
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DOI：
10.1523/jneurosci.0723-06.2006
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发表时间：
2006-08-02
影响因子：
5.3
通讯作者：
Plenz, Dietmar
中科院分区：
文献类型：
--
作者：
Stewart, Craig V.;Plenz, Dietmar
前额叶皮质(PFC)的功能，如工作记忆、注意力选择和记忆提取，在很大程度上依赖于多巴胺和NMDA受体的激活，其药理曲线呈倒U形。尽管PFC中的单个神经元反应已经显示了这种特征的某些方面，但还没有发现遵循多巴胺-NMDA依赖的网络动态。用微电极阵列记录局部场电位(LFP)的方法，研究了成年大鼠急性内侧PFC脑片的神经元网络活动。多巴胺或多巴胺D-1激动剂SKF38393[(+/-)-1-苯基-2，3，4，5-四氢-(1H)-3-苯并卓-7，8-二醇盐酸盐]与NMDA联合应用主要在皮层浅层诱发自发性LFP。单个电极上的LFP具有尖锐的负峰的特征，这些负峰在时间上聚集在电极上，显示出阵列上不同的时空模式。这种模式的形成需要快速的GABA能传递，多巴胺D-1和NMDA受体的共同激活，并依赖于多巴胺的倒U形分布。在中等浓度的多巴胺或多巴胺D-1激动剂时，图案大小分布形成指数α=-1.5的幂规律，表明图案以神经元雪崩的形式组织，从而使网络中的空间相关性最大化。在较低或较高浓度下，α比-1.5更负，表明空间相关性降低。同样，在中等浓度的多巴胺下，特定雪崩的雪崩率和复发频率最高，其复发频率遵循斜率为-2.4的“幂定律”重尾分布。我们认为，依赖多巴胺的NMDA依赖的特定雪崩在皮质浅层的自发复发可能促进PFC功能的整合和联合。
Prefrontal cortex (PFC) functions, such as working memory, attention selection, and memory retrieval, depend critically on dopamine and NMDA receptor activation by way of an inverted-U-shaped pharmacological profile. Although single neuron responses in the PFC have shown some aspects of this profile, a network dynamic that follows the dopamine-NMDA dependence has not been identified. We studied neuronal network activity in acute medial PFC slices of adult rats by recording local field potentials (LFPs) with microelectrode arrays. Bath application of dopamine or the dopamine D-1 agonist SKF38393 [( +/-)-1-phenyl- 2,3,4,5-tetrahydro-(1H)-3-benzazepine- 7,8-diol hydrochloride] in combination with NMDA induced spontaneous LFPs predominantly in superficial cortex layers. The LFPs at single electrodes were characterized by sharp negative peaks that were clustered in time across electrodes revealing diverse spatiotemporal patterns on the array. The pattern formation required fast GABAergic transmission, coactivation of the dopamine D-1 and NMDA receptor, and depended in an inverted-U profile on dopamine. At moderate concentrations of dopamine or the dopamine D-1 agonist, the pattern size distribution formed a power law with exponent alpha = -1.5, indicating that patterns are organized in the form of neuronal avalanches, thereby maximizing spatial correlations in the network. At lower or higher concentrations, alpha was more negative than - 1.5, indicating reduced spatial correlations. Likewise, at moderate dopamine concentrations, the avalanche rate and recurrence of specific avalanches was maximal with recurrence frequencies after a "power law"-like heavy-tail distribution with a slope of -2.4. We suggest that the dopamine-NMDA-dependent spontaneous recurrence of specific avalanches in superficial cortical layers might facilitate integrative and associative aspects of PFC functions.