Janssen Marcus L F, Temel Yasin, Delaville Claire, Zwartjes Daphne G M, Heida Tjitske, De Deurwaerdère Philippe, Visser-Vandewalle Veerle, Benazzouz Abdelhamid
Univ. de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, 146, Rue Léo-Saignat, 33000, Bordeaux Cedex, France.
CNRS, Institut des Maladies Neurodégénératives, UMR 5293, 33000, Bordeaux, France.
Brain Struct Funct. 2017 Aug;222(6):2473-2485. doi: 10.1007/s00429-016-1351-5. Epub 2016 Dec 24.
The subthalamic nucleus (STN) receives monosynaptic glutamatergic afferents from different areas of the cortex, known as the "hyperdirect" pathway. The STN has been divided into three distinct subdivisions, motor, limbic, and associative parts in line with the concept of parallel information processing. The extent to which the parallel information processing coming from distinct cortical areas overlaps in the different territories of the STN is still a matter of debate and the proposed role of dopaminergic neurons in maintaining the coherence of responses to cortical inputs in each territory is not documented. Using extracellular electrophysiological approaches, we investigated to what degree the motor and non-motor regions in the STN are segregated in control and dopamine (DA) depleted rats. We performed electrical stimulation of different cortical areas and recorded STN neuronal responses. We showed that motor and non-motor cortico-subthalamic pathways are not fully segregated, but partially integrated in the rat. This integration was mostly present through the indirect pathway. The spatial distribution and response latencies were the same in sham and 6-hydroxydopamine lesioned animals. The inhibitory phase was, however, less apparent in the lesioned animals. In conclusion, this study provides the first evidence that motor and non-motor cortico-subthalamic pathways in the rat are not fully segregated, but partially integrated. This integration was mostly present through the indirect pathway. We also show that the inhibitory phase induced by GABAergic inputs from the external segment of the globus pallidus is reduced in the DA-depleted animals.
丘脑底核（STN）接受来自皮层不同区域的单突触谷氨酸能传入纤维，即所谓的“超直接”通路。根据并行信息处理的概念，STN已被分为三个不同的亚区，即运动、边缘和联合部分。来自不同皮层区域的并行信息处理在STN的不同区域重叠的程度仍存在争议，并且多巴胺能神经元在维持每个区域对皮层输入反应的连贯性方面所提出的作用尚无文献记载。我们使用细胞外电生理方法，研究了在对照大鼠和多巴胺（DA）耗竭的大鼠中，STN中的运动和非运动区域在多大程度上是分离的。我们对不同的皮层区域进行电刺激，并记录STN神经元的反应。我们发现，在大鼠中，运动和非运动的皮质-丘脑底核通路并未完全分离，而是部分整合。这种整合主要通过间接通路存在。假手术组和6-羟基多巴胺损伤组动物的空间分布和反应潜伏期相同。然而，在损伤动物中，抑制期不太明显。总之，本研究提供了首个证据，表明大鼠中的运动和非运动皮质-丘脑底核通路并非完全分离，而是部分整合。这种整合主要通过间接通路存在。我们还表明，在DA耗竭的动物中，来自苍白球外侧段的GABA能输入所诱导的抑制期减少。
