Abstract:
Molecular layer interneurons (MLIs) account for approximately 80% of the inhibitory interneurons in the cerebellar cortex and are vital to cerebellar processing. MLIs are thought to primarily inhibit Purkinje cells (PCs) and suppress the plasticity of synapses onto PCs. MLIs also inhibit, and are electrically coupled to, other MLIs, but the functional significance of these connections is not known. Here, we find that two recently recognized MLI subtypes, MLI1 and MLI2, have a highly specialized connectivity that allows them to serve distinct functional roles. MLI1s primarily inhibit PCs, are electrically coupled to each other, fire synchronously with other MLI1s on the millisecond timescale in vivo, and synchronously pause PC firing. MLI2s are not electrically coupled, primarily inhibit MLI1s and disinhibit PCs, and are well suited to gating cerebellar-dependent behavior and learning. The synchronous firing of electrically coupled MLI1s and disinhibition provided by MLI2s require a major re-evaluation of cerebellar processing.
摘要:
分子层中间神经元(MLI)约占小脑皮质中抑制性中间神经元的80%,对小脑加工至关重要。MLI被认为主要抑制浦肯野细胞(PC)并抑制突触到PC上的可塑性。MLIs也抑制,并电耦合到,其他MLI,但是这些连接的功能意义尚不清楚。这里,我们发现了两个最近发现的MLI亚型,MLI1和MLI2具有高度专业化的连接性,使它们能够充当不同的功能角色。MLI1主要抑制PC,彼此电耦合,在体内毫秒时间尺度上与其他MLI1同步发射,并同步暂停PC点火。MLI2没有电耦合,主要抑制MLI1和抑制PC,非常适合控制小脑依赖的行为和学习。电耦合的MLI1的同步发射和MLI2提供的去抑制需要对小脑处理进行重大的重新评估。