Precision of Discrete and Rhythmic Forelimb Movements Requires a Distinct Neuronal Subpopulation in the Interposed Anterior Nucleus

Publication date: 27 February 2018
Source:Cell Reports, Volume 22, Issue 9
Author(s): Aloysius Y.T. Low, Ayesha R. Thanawalla, Alaric K.K. Yip, Jinsook Kim, Kelly L.L. Wong, Martesa Tantra, George J. Augustine, Albert I. Chen
The deep cerebellar nuclei (DCN) represent output channels of the cerebellum, and they transmit integrated sensorimotor signals to modulate limb movements. But the functional relevance of identifiable neuronal subpopulations within the DCN remains unclear. Here, we examine a genetically tractable population of neurons in the mouse interposed anterior nucleus (IntA). We show that these neurons represent a subset of glutamatergic neurons in the IntA and constitute a specific element of an internal feedback circuit within the cerebellar cortex and cerebello-thalamo-cortical pathway associated with limb control. Ablation and optogenetic stimulation of these neurons disrupt efficacy of skilled reach and locomotor movement and reveal that they control positioning and timing of the forelimb and hindlimb. Together, our findings uncover the function of a distinct neuronal subpopulation in the deep cerebellum and delineate the anatomical substrates and kinematic parameters through which it modulates precision of discrete and rhythmic limb movements.

Graphical abstract

Teaser

The deep cerebellar nuclei transmit integrated sensorimotor signals to modify movement. Using a urocortin 3::Cre mouse line, Low et al. identify a subpopulation of glutamatergic neurons in the interposed anterior nucleus required for specific kinematic parameters of rhythmic and discrete movement via connectivity with forelimb-associated nucleocortical and nucleofugal pathways.


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