Department of Physiology and Biophysics, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, United States.
Elife. 2021 Sep 20;10:e66231. doi: 10.7554/eLife.66231.
The cerebellum consists of parallel circuit modules that contribute to diverse behaviors, spanning motor to cognitive. Recent work employing cell-type-specific tracing has identified circumscribed output channels of the cerebellar nuclei (CbN) that could confer tight functional specificity. These studies have largely focused on excitatory projections of the CbN, however, leaving open the question of whether inhibitory neurons also constitute multiple output modules. We mapped output and input patterns to intersectionally restricted cell types of the interposed and adjacent interstitial nuclei in mice. In contrast to the widespread assumption of primarily excitatory outputs and restricted inferior olive-targeting inhibitory output, we found that inhibitory neurons from this region ramified widely within the brainstem, targeting both motor- and sensory-related nuclei, distinct from excitatory output targets. Despite differences in output targeting, monosynaptic rabies tracing revealed largely shared afferents to both cell classes. We discuss the potential novel functional roles for inhibitory outputs in the context of cerebellar theory.
小脑由平行的电路模块组成，这些模块有助于各种行为，包括运动到认知。最近采用细胞类型特异性示踪的研究已经确定了小脑核（CbN）的限定输出通道，这些通道可能赋予了紧密的功能特异性。这些研究主要集中在 CbN 的兴奋性投射上，然而，抑制性神经元是否也构成多个输出模块仍未解决。我们在小鼠的间位核和相邻间质核中映射了交叉限制的细胞类型的输出和输入模式。与主要兴奋性输出和限制橄榄下核靶向抑制性输出的广泛假设相反，我们发现来自该区域的抑制性神经元在脑干中广泛分枝，靶向运动和感觉相关核，与兴奋性输出靶标不同。尽管输出靶向存在差异，但单突触狂犬病示踪显示，这两类细胞都有很大比例的共同传入。我们讨论了抑制性输出在小脑理论背景下的潜在新功能作用。
