Santaniello S, Gale J T, Montgomery E B, Sarma S V
Institute of Computational Medicine, Johns Hopkins University, Baltimore, MD 21218, USA.
Annu Int Conf IEEE Eng Med Biol Soc. 2010;2010:2065-8. doi: 10.1109/IEMBS.2010.5626354.
Striatum (STR) is the major input stage of the basal ganglia (BG). It combines information from cortex, subthalamic nucleus (STN) and external globus pallidus (GPe), and projects to the output stages of the BG, where selection between concurrent motor programs is performed. Parkinson's disease (PD) reduces the concentration of dopamine (DA, a neurotransmitter) in STR and changes in the level of DA correlate with the onset of PD motor disorders. Though STR plays a pivotal role in BG, its behavior under PD and Deep Brain Stimulation (DBS) is still unclear. We develop point-process models of the STR neurons as a function of the activity in GPe, cortex, and DBS. We use single unit recordings from a monkey under STN DBS at different frequencies before and after treatment with 1-methyl-4-phenyl-1,2,3,6-tetrahydro-pyridine (MPTP) to develop PD motor symptoms. The models suggest that STR neurons have prominent bursting activity in normal conditions, positive correlation with cortex (3-10 ms delay), and mild negative correlation with GPe (1-5 ms lag). DA depletion evokes 30-60 Hz oscillations, and increases the propensity of each neuron to be inhibited by surrounding neurons. DBS elicits antidromical activation, masks existent dynamics, reinforces dependencies between nuclei, and entrains at the stimulation frequency in both conditions.
纹状体（STR）是基底神经节（BG）的主要输入阶段。它整合来自皮质、丘脑底核（STN）和外侧苍白球（GPe）的信息，并投射到BG的输出阶段，在那里对同时存在的运动程序进行选择。帕金森病（PD）会降低纹状体中多巴胺（DA，一种神经递质）的浓度，DA水平的变化与PD运动障碍的发作相关。尽管纹状体在基底神经节中起着关键作用，但其在PD和深部脑刺激（DBS）下的行为仍不清楚。我们开发了纹状体神经元的点过程模型，作为GPe、皮质和DBS活动的函数。我们使用一只猴子在接受1-甲基-4-苯基-1,2,3,6-四氢吡啶（MPTP）治疗前后不同频率的丘脑底核DBS下的单单元记录来模拟PD运动症状。模型表明，纹状体神经元在正常情况下具有显著的爆发活动，与皮质呈正相关（延迟3 - 10毫秒），与GPe呈轻度负相关（滞后1 - 5毫秒）。多巴胺耗竭会引发30 - 60赫兹的振荡，并增加每个神经元被周围神经元抑制的倾向。DBS引发逆向激活，掩盖现有的动态，加强核之间的依赖性，并在两种情况下都以刺激频率进行同步。
