Gao Zhenyu, Proietti-Onori Martina, Lin Zhanmin, Ten Brinke Michiel M, Boele Henk-Jan, Potters Jan-Willem, Ruigrok Tom J H, Hoebeek Freek E, De Zeeuw Chris I
Department of Neuroscience, Erasmus MC, 3015 CN Rotterdam, the Netherlands.
Department of Neuroscience, Erasmus MC, 3015 CN Rotterdam, the Netherlands.
Neuron. 2016 Feb 3;89(3):645-57. doi: 10.1016/j.neuron.2016.01.008.
Closed-loop circuitries between cortical and subcortical regions can facilitate precision of output patterns, but the role of such networks in the cerebellum remains to be elucidated. Here, we characterize the role of internal feedback from the cerebellar nuclei to the cerebellar cortex in classical eyeblink conditioning. We find that excitatory output neurons in the interposed nucleus provide efference-copy signals via mossy fibers to the cerebellar cortical zones that belong to the same module, triggering monosynaptic responses in granule and Golgi cells and indirectly inhibiting Purkinje cells. Upon conditioning, the local density of nucleocortical mossy fiber terminals significantly increases. Optogenetic activation and inhibition of nucleocortical fibers in conditioned animals increases and decreases the amplitude of learned eyeblink responses, respectively. Our data show that the excitatory nucleocortical closed-loop circuitry of the cerebellum relays a corollary discharge of premotor signals and suggests an amplifying role of this circuitry in controlling associative motor learning.
皮质和皮质下区域之间的闭环回路可以促进输出模式的精确性，但这种网络在小脑中的作用仍有待阐明。在这里，我们在经典眨眼条件反射中表征了从小脑核到小脑皮质的内部反馈的作用。我们发现，间位核中的兴奋性输出神经元通过苔藓纤维向属于同一模块的小脑皮质区域提供传出副本信号，触发颗粒细胞和高尔基细胞中的单突触反应，并间接抑制浦肯野细胞。在条件反射后，核皮质苔藓纤维终末的局部密度显著增加。对条件反射动物的核皮质纤维进行光遗传学激活和抑制，分别增加和降低了习得眨眼反应的幅度。我们的数据表明，小脑的兴奋性核皮质闭环回路传递运动前信号的伴随放电，并表明该回路在控制联合运动学习中具有放大作用。
