Moënne-Loccoz Cristóbal, Astudillo-Valenzuela Carolina, Skovgård Katrine, Salazar-Reyes Carolina A, Barrientos Sebastian A, García-Núñez Ximena P, Cenci M Angela, Petersson Per, Fuentes-Flores Rómulo A
Biomedical Neuroscience Institute, University of Chile, Santiago, Chile.
Laboratorio de Control Motor y Neuromodulación, Facultad de Medicina, Universidad de Chile, Santiago, Chile.
Front Syst Neurosci. 2020 Aug 13;14:56. doi: 10.3389/fnsys.2020.00056. eCollection 2020.
Oscillatory neural activity in the cortico-basal ganglia-thalamocortical (CBGTC) loop is associated with the motor state of a subject, but also with the availability of modulatory neurotransmitters. For example, increased low-frequency oscillations in Parkinson's disease (PD) are related to decreased levels of dopamine and have been proposed as biomarkers to adapt and optimize therapeutic interventions, such as deep brain stimulation. Using neural oscillations as biomarkers require differentiating between changes in oscillatory patterns associated with parkinsonism vs. those related to a subject's motor state. To address this point, we studied the correlation between neural oscillatory activity in the motor cortex and striatum and varying degrees of motor activity under normal and parkinsonian conditions. Using rats with bilateral or unilateral 6-hydroxydopamine lesions as PD models, we correlated the motion index (MI)-a measure based on the physical acceleration of the head of rats-to the local field potential (LFP) oscillatory power in the 1-80 Hz range. In motor cortices and striata, we observed a robust correlation between the motion index and the oscillatory power in two main broad frequency ranges: a low-frequency range [5.0-26.5 Hz] was negatively correlated to motor activity, whereas a high-frequency range [35.0-79.9 Hz] was positively correlated. We observed these correlations in both normal and parkinsonian conditions. In addition to these general changes in broad-band power, we observed a more restricted narrow-band oscillation [25-40 Hz] in dopamine-denervated hemispheres. This oscillation, which seems to be selective to the parkinsonian state, showed a linear frequency dependence on the concurrent motor activity level. We conclude that, independently of the parkinsonian condition, changes in broad-band oscillatory activities of cortico-basal ganglia networks (including changes in the relative power of low- and high-frequency bands) are closely correlated to ongoing motions, most likely reflecting he operations of these neural circuits to control motor activity. Hence, biomarkers based on neural oscillations should focus on specific features, such as narrow frequency bands, to allow differentiation between parkinsonian states and physiological movement-dependent circuit modulation.
皮质-基底神经节-丘脑皮质(CBGTC)环路中的振荡性神经活动不仅与受试者的运动状态相关,还与调节性神经递质的可用性有关。例如,帕金森病(PD)中低频振荡的增加与多巴胺水平降低有关,并已被提议作为适应和优化治疗干预措施(如深部脑刺激)的生物标志物。将神经振荡用作生物标志物需要区分与帕金森综合征相关的振荡模式变化和与受试者运动状态相关的变化。为了解决这一问题,我们研究了正常和帕金森病状态下运动皮层和纹状体中的神经振荡活动与不同程度运动活动之间的相关性。使用双侧或单侧6-羟基多巴胺损伤的大鼠作为PD模型,我们将运动指数(MI)(一种基于大鼠头部物理加速度的测量方法)与1-80Hz范围内的局部场电位(LFP)振荡功率相关联。在运动皮层和纹状体中,我们在两个主要的宽频率范围内观察到运动指数与振荡功率之间存在强烈的相关性:低频范围[5.0-26.5Hz]与运动活动呈负相关,而高频范围[35.0-79.9Hz]呈正相关。我们在正常和帕金森病状态下均观察到了这些相关性。除了宽带功率的这些一般变化外,我们在多巴胺去神经支配的半球中观察到了更受限的窄带振荡[25-40Hz]。这种振荡似乎对帕金森病状态具有选择性,显示出与同时存在的运动活动水平呈线性频率依赖性。我们得出结论,无论帕金森病状态如何,皮质-基底神经节网络的宽带振荡活动变化(包括低频和高频带相对功率的变化)都与正在进行的运动密切相关,很可能反映了这些神经回路控制运动活动的运作。因此,基于神经振荡的生物标志物应关注特定特征,如窄频带,以便区分帕金森病状态和生理运动依赖性电路调制