Brainstem nucleus MdV mediates skilled forelimb motor tasks

NATURE

Volume 508, Issue 7496, Pages 351-+

NATURE PUBLISHING GROUP

Translating the behavioural output of the nervous system into movement involves interaction between brain and spinal; cord. The brainstem provides an essential bridge between the two structures; but circuit-level organization and function; of this intermediary system remain poorly understood. Here we use intersectional virus tracing and genetic strategies in; mice to reveal a selective synaptic connectivity matrix between brainstem substructures and functionally distinct spinal; motor neurons that regulate limb movement. The brainstem nucleus medullary reticular formation ventral part (MdV); stands out as specifically targeting subpopulations of forelimb-innervating motor neurons. Its glutamatergic premotor; neurons receive synaptic input from key upper motor centres and are recruited during motor tasks. Selective neuronal; ablation or silencing experiments reveal that MdV is critically important specifically for skilled motor behaviour; including; accelerating rotarod and single-food-pellet reaching tasks. Our results indicate that distinct premotor brainstem; nuclei access spinal subcircuits to mediate task-specific aspects of motor programs.

Multidisciplinary Sciences

1. Human Frontier Science Program
2. European Research Council Advanced Grant
3. Swiss National Science Foundation
4. Kanton Basel-Stadt
5. Novartis Research Foundation