Dynamic changes in the cortex-basal ganglia network after dopamine depletion in the rat
Dynamic changes in the cortex-basal ganglia network after dopamine depletion in the rat
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DOI：
10.1152/jn.90466.2008
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发表时间：
2008-07-01
影响因子：
2.5
通讯作者：
Boraud, Thomas
中科院分区：
文献类型：
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作者：
Dejean, Cyril;Gross, Christian E.;Boraud, Thomas
众所周知，帕金森综合征与基底节神经元活动和局部场电位的时间模式改变有关。在帕金森病患者和这种疾病的动物模型中，在不同的BG核中观察到同步振荡的增加。然而，这种现象背后的机制仍然不清楚。这项研究调查了帕金森氏病啮齿动物模型大脑皮质-BG网络的功能连接。在自由活动大鼠的运动皮质、纹状体和黑质网状部(SNR)同时记录单个神经元和局部场电位，并用高压纺锤波(HVSS)比较多巴胺能神经元耗竭前后的信号传递。结果表明，损毁多巴胺能使BG的振荡同步性显著增强：结构对之间的一致性显着增加，振荡自相关图和交叉相关图的百分比显著增加。人类免疫缺陷综合征的发作也更多、更长。这些变化与SNR对皮质激活的反应潜伏期缩短有关，从40.5+/-4.8毫秒缩短到10.2+/-1.07毫秒。这一结果表明，在正常情况下，SNR神经元可能是由间接通路的晚期输入驱动的；然而，在损伤后，其较短的潜伏期也表明超直接通路的过度激活。这项研究证实，多巴胺耗竭后，BG中的神经元信号传递发生了变化，但也在细胞水平上为这些变化提供了定性证据。
It is well established that parkinsonian syndrome is associated with alterations in the temporal pattern of neuronal activity and local field potentials in the basal ganglia (BG). An increase in synchronized oscillations has been observed in different BG nuclei in parkinsonian patients and animal models of this disease. However, the mechanisms underlying this phenomenon remain unclear. This study investigates the functional connectivity in the cortex-BG network of a rodent model of Parkinson's disease. Single neurons and local field potentials were simultaneously recorded in the motor cortex, the striatum, and the substantia nigra pars reticulata (SNr) of freely moving rats, and high-voltage spindles (HVSs) were used to compare signal transmission before and after dopaminergic depletion. It is shown that dopaminergic lesion results in a significant enhancement of oscillatory synchronization in the BG: the coherence between pairs of structures increased significantly and the percentage of oscillatory auto- and cross-correlograms. HVS episodes were also more numerous and longer. These changes were associated with a shortening of the latency of SNr response to cortical activation, from 40.5 +/- 4.8 to 10.2 +/- 1.07 ms. This result suggests that, in normal conditions, SNr neurons are likely to be driven by late inputs from the indirect pathway; however, after the lesion, their shorter latency also indicates an overactivation of the hyperdirect pathway. This study confirms that neuronal signal transmission is altered in the BG after dopamine depletion but also provides qualitative evidence for these changes at the cellular level.