arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1009.4516q-bio.NC
收藏

基底神经节建模用于理解帕金森病的到达运动

Modeling Basal Ganglia for understanding Parkinsonian Reaching Movements

K. N. Magdoom, D. Subramanian, V. S. Chakravarthy, B. Ravindran, Shun-ichi Amari, N. Meenakshisundaram

摘要:

我们提出了一个计算模型,强调基底神经节(BG)在产生简单的达到运动的作用。该模型在强化学习(RL)框架内进行铸造,RL组件和神经解剖学之间的对应关系如下:黑质多巴胺信号作为时间差误差,纹状体作为Critic的基底,运动皮层作为Actor。这种神经生物学解释的一个关键特征是我们的假设,即间接途径是探索者。混沌活动,起源于模型的间接路径部分,驱动着手臂的游荡和探索运动,因此直接路径有利于开发,而间接路径有利于探索。随着训练的进行,运动皮层变得越来越独立于BG的校正影响。到达轨迹显示出随着训练而减少的可变性。与帕金森病(PD)相关的到达运动是通过(a)减少多巴胺和(b)通过将其从混沌切换到周期性行为来降低间接通路动力学的复杂性来模拟的。在模拟PD条件下,手臂表现出PD运动症状,如震颤、运动迟缓和下冲。该模型反映了PD是一种动态疾病的概念。

英文摘要:

We present a computational model that highlights the role of basal ganglia (BG) in generating simple reaching movements. The model is cast within the reinforcement learning (RL) framework with the correspondence between RL components and neuroanatomy as follows: dopamine signal of substantia nigra pars compacta as the Temporal Difference error, striatum as the substrate for the Critic, and the motor cortex as the Actor. A key feature of this neurobiological interpretation is our hypothesis that the indirect pathway is the Explorer. Chaotic activity, originating from the indirect pathway part of the model, drives the wandering, exploratory movements of the arm. Thus the direct pathway subserves exploitation while the indirect pathway subserves exploration. The motor cortex becomes more and more independent of the corrective influence of BG, as training progresses. Reaching trajectories show diminishing variability with training. Reaching movements associated with Parkinson's disease (PD) are simulated by (a) reducing dopamine and (b) degrading the complexity of indirect pathway dynamics by switching it from chaotic to periodic behavior. Under the simulated PD conditions, the arm exhibits PD motor symptoms like tremor, bradykinesia and undershoot. The model echoes the notion that PD is a dynamical disease.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑