A basic study of the motor disturbance in basal ganglia diseases

我们计划研究大鼠丘脑束旁核（Pf）的突触组织，其项目的纹状体，与束旁传入。将生物素化葡聚糖胺（BDA）注入Pf主要传入来源的上级丘（SC）或脚桥被盖核（PPN）后，在Pf外侧部出现大量BDA标记的轴突和轴突终末，电镜下标记的轴突终末均含有圆形突触囊泡，形成不对称的突触。比较SC和PPN的传入终末，前者似乎比后者大，SC终末比PPN终末更倾向于位于树突的近端。将辣根过氧化物酶标记的麦胚凝集素（WGA-HRP）和BDA分别注入纹状体和SC，观察到BDA标记的终末与WGA-HRP标记的Pf神经元形成突触。证实了丘-束旁-纹状体的连续投射。当将WGA-HKP和BDA分别注入SC和PPN时，观察到来自两个核的轴突终末与Pf神经元的单个树突突触。这一事实意味着SC和PPN传入会聚到单个Pf神经元上。因此，可以认为SC的视觉运动和定向运动功能以及PPN的运动功能都整合在PF中，这些信息可能通过基底神经节传递到纹状体，再通过基底神经节传递到运动皮层。现在我们可以解释Pf函数的一部分。

We planned to study the synaptic organization of the rat parafascicular nucleus (Pf) of the thalamus, which projects to the striatum, in relation to parafascicular afferents. After injections of biotinylated dextran amine (BDA) into the superior colliculus (SC) or the pedunculopontine tegmental nucleus (PPN), both of which are main afferent sources of the Pf, numerous BDA-labeled axons and axon terminals appeared in the lateral part of the Pf. Electron microscopically all of the labeled axon terminals contained round synaptic vesicles and made asymmetric synapses. Comparing SC and PPN afferent terminals, the former seemed larger than the latter, and SC terminals tended to be located at more proximal portion of dendrites than PPN terminals. When wheatgerm agglutinin conjugated to horseradish peroxidase (WGA-HRP) and BDA were injected into the striatum and SC, respectively, BDA-labeled terminals were observed to synapse with WGA-HRP labeled Pf neurons. Thus, the serial colliculo-parafasciculo-striatal projection was proved. When WGA-HKP and BDA were injected into the SC and PPN, respectively, axon terminals from both nuclei observed to synapse with a single dendrite of Pf neurons. This fact means that SC and PPN afferents converged onto a single Pf neuron. It is conceirvable, therefore, both ocular and orientation movements of the SC function, and locomotion of the PPN function are integrated in the Pf. Then this kind of information might be sent to the striatum, and conveyed to the motor cortex via the basal ganglia circuitry. Now we could explain a part of the Pf function.