Department of Biotechnology, IIT Madras, Chennai, Tamil Nadu, India.
Prog Brain Res. 2013;202:389-414. doi: 10.1016/B978-0-444-62604-2.00020-4.
We present a model of basal ganglia (BG) that departs from the classical Go/NoGo picture of the function of its key pathways-the Direct and Indirect Pathways (DP and IP). Between the Go and NoGo regimes, we posit a third Explore regime, which denotes random exploration of action alternatives. Striatal dopamine (DA) is assumed to switch between DP and IP activation. The IP is modeled as a loop of the subthalamic nucleus (STN) and the Globus Pallidus externa (GPe). Simulations reveal that while the model displays Go and NoGo regimes for extreme values of DA, at intermediate values of DA, it exhibits exploratory behavior, which originates from the chaotic activity of the STN-GPe loop. We describe a series of BG models based on Go/Explore/NoGo approach, to explain the role of BG in three cases: (1) a simple action selection task, (2) reaching, and (3) willed action.
我们提出了一个基底神经节（BG）的模型，该模型偏离了其关键途径——直接途径和间接途径（DP 和 IP）的经典 Go/NoGo 功能图景。在 Go 和 NoGo 状态之间，我们假设了第三种探索状态，表示对动作选择的随机探索。纹状体多巴胺（DA）被假定在 DP 和 IP 激活之间切换。IP 被建模为丘脑下核（STN）和苍白球外（GPe）的循环。模拟结果表明，虽然该模型对于 DA 的极端值显示出 Go 和 NoGo 状态，但在 DA 的中间值时，它表现出探索行为，这种行为源于 STN-GPe 循环的混沌活动。我们描述了一系列基于 Go/Explore/NoGo 方法的 BG 模型，以解释 BG 在三种情况下的作用：（1）简单的动作选择任务，（2）到达，和（3）意愿动作。
