Department of Neurology, University of Minnesota, Minneapolis, MN, 55455, USA.
Department of Neurology, University of Iowa, Iowa City, IA, USA.
Eur J Neurosci. 2018 Oct;48(8):2869-2878. doi: 10.1111/ejn.13853. Epub 2018 Feb 8.
Dopamine is an important neurotransmitter that maintains the balance within the basal ganglia between the direct pathway, which promotes movement, and the indirect pathway, which inhibits movement. Degeneration of dopaminergic neurons in the substantia nigra increases the influence of the indirect pathway, resulting in motor dysfunction in Parkinson's disease (PD). The direct and indirect pathways are composed of basal ganglia and thalamic nuclei, which are interconnected via independent parallel loop circuits with cortical areas and often referred to as cortico-basal ganglia-thalamic (CBT) neural circuits. CBT circuits have been useful in generating hypotheses to describe slowness in PD. Recent work has focused on aberrant neural oscillations within CBT circuits. Although beta (13-30 Hz) oscillations are a common feature of the CBT network, there is growing evidence that abnormally exaggerated beta oscillations, observed after dopamine loss in the CBT circuits, may contribute to motor symptoms of PD. Disruption of abnormal beta oscillations has been associated with the improvement of motor functions during pharmacological treatments, surgical lesions, and electrical stimulation. However, it is not clear how abnormal oscillations originate in the CBT motor network and resonate specifically in the beta band after the loss of dopamine. Most studies have addressed these questions by simultaneous recordings of oscillations in the motor cortex, basal ganglia nuclei, and motor regions of the thalamus in animal models of parkinsonism as well as in PD patients. This review further discusses previous and current studies of the changes in oscillatory activity at the level of CBT neural network in PD.
多巴胺是一种重要的神经递质,它在基底神经节中维持着直接通路和间接通路之间的平衡,直接通路促进运动,间接通路抑制运动。黑质中多巴胺能神经元的退化增加了间接通路的影响,导致帕金森病(PD)的运动功能障碍。直接和间接通路由基底神经节和丘脑核组成,它们通过与皮质区域相互连接的独立平行回路进行相互连接,通常被称为皮质-基底神经节-丘脑(CBT)神经回路。CBT 回路在产生描述 PD 中运动迟缓的假设方面非常有用。最近的工作集中在 CBT 回路中的异常神经振荡上。尽管β(13-30 Hz)振荡是 CBT 网络的一个共同特征,但越来越多的证据表明,CBT 回路中多巴胺丧失后观察到的异常放大的β振荡可能导致 PD 的运动症状。异常β振荡的破坏与运动功能的改善有关,包括药物治疗、手术损伤和电刺激。然而,目前尚不清楚 CBT 运动网络中的异常振荡是如何产生的,以及在多巴胺丧失后如何专门在β频带中产生共振。大多数研究通过在帕金森病动物模型以及 PD 患者中同时记录运动皮层、基底神经节核和丘脑运动区域的振荡,来解决这些问题。这篇综述进一步讨论了 CBT 神经网络中振荡活动在 PD 水平上的变化的先前和当前研究。