Long-term potentiation of the corticorubral synapse produced by cerebro-cerebellar communication

红核位于哺乳动物脑小脑通讯系统的关键位置。猫的RN接受小脑间位核和感觉运动皮质和联想皮质的直接投射。前者在胞体或近端树突上形成突触，后者在RN的外周树突上形成突触。据报道，皮质纤维的破伤风产生了持续几分钟的由皮质突触介导的兴奋性突触后电位（EPSPs）的破伤风后增强。然而，在突触中未发现长期增强（LTP）。在本研究中，我们证明了皮质纤维和皮质间纤维的强直刺激联合诱导皮质epsp的LTP。LTP可能专门发生在皮质皮质突触，因为皮质间epsp和RN细胞的输入电阻均未发生变化。因此，我们认为，大脑和小脑输出的联合活动导致了皮质传递效果的长期变化，这可能是由RN介导的自主运动的运动学习的基础。

The red nucleus (RN) is located at the key position in the cerebrocerebellar communication system in mammals. The RN in cat receives direct projection from both the interpositus nucleus of cerebellum and sensorimotor and association cortices. The former makes synapses on the soma or proximal dendrites and the latter on the peripheral dendrites of the RN.It was reported that tetanization of the corticorubral fibers produced posttetanic potentiation, which lasted a few minutes, of the excitatory postsynaptic potentials (EPSPs) mediated by the corticorubral synapses. However, a long-term potentiation (LTP) has not been found at the synapses. In the present study, we demonstrated that conjunction of the tetanic stimulation of the corticorubral fibers and interpositorubral fibers induces an LTP of the corticorubral EPSPs. The LTP likely occurs specifically at the corticorubral synapses, since there was no change in either the interpositorubral EPSPs or input resistance of the RN cells. Thus, it is suggested that the conjunctive activities of the cerebral and cerebellar outputs induce a long-lasting change in the efficacy of corticorubral transmission, which may underlie motor learning of the voluntary movement mediated by the RN.