Department of Neuroscience, University of Minnesota, Minneapolis, MN, 55414, USA.
Brain Science Center, Veterans Administration Medical Center, One Veterans Drive, Bldg 49, Rm 240, Minneapolis, MN, 55417-2399, USA.
Cerebellum. 2020 Jun;19(3):401-408. doi: 10.1007/s12311-020-01108-8.
The cerebellum and the basal ganglia play an important role in the control of voluntary eye movement associated with complex behavior, but little is known about how cerebellar projections project to cortical eye movement areas. Here we used retrograde transneuronal transport of rabies virus to identify neurons in the cerebellar nuclei that project via the thalamus to supplementary eye field (SEF) of the frontal cortex of macaques. After rabies injections into the SEF, many neurons in the restricted region, the ventral aspects of the dentate nucleus (DN), the caudal pole of the DN, and the posterior interpositus nucleus (PIN) were labeled disynaptically via the thalamus, whereas no neuron labeling was found in the anterior interpositus nucleus (AIN). The distribution of the labeled neurons was dorsoventrally different from that of DN and PIN neurons labeled from the motor cortex. In the basal ganglia, a large number of labeled neurons were confined to the dorsomedial portion of the internal segment of the globus pallidus (GPi) as more neurons were labeled in the inner portion of the GPi (GPii) than in the outer portion of the GPi (GPio). This is the first evidence of a projection between cerebellum/basal ganglia and the SEF that could enable the cerebellum to modulate the cognitive control of voluntary eye movement.
小脑和基底神经节在与复杂行为相关的自主眼球运动控制中起着重要作用，但对于小脑投射如何投射到皮质眼球运动区域知之甚少。在这里，我们使用狂犬病毒逆行转导来识别通过丘脑投射到灵长类动物额皮质补充眼区（SEF）的小脑核神经元。在 SEF 中注射狂犬病毒后，在受限区域（齿状核腹侧部分、齿状核尾极和后中间核）和丘脑的许多神经元被双突触标记，而在前中间核（AIN）中未发现神经元标记。标记神经元的分布在背腹方向上与来自运动皮层标记的 DN 和 PIN 神经元的分布不同。在基底神经节中，大量标记神经元局限于苍白球内节（GPi）的背内侧部分，因为在 GPi 的内部分（GPii）标记的神经元比在 GPi 的外部分（GPio）更多。这是小脑/基底神经节与 SEF 之间存在投射的第一个证据，这使得小脑能够调节自主眼球运动的认知控制。
