Orofacial Movements Involve Parallel Corticobulbar Projections from Motor Cortex to Trigeminal Premotor Nuclei.

ABSTRACT: How do neurons in orofacial motor cortex (MCtx) orchestrate behaviors? We show that focal activation of MCtx corticobulbar neurons evokes behaviorally relevant concurrent movements of the forelimb, jaw, nose, and vibrissae. The projections from different locations in MCtx form gradients of boutons across premotor nuclei spinal trigeminal pars oralis (SpVO) and interpolaris rostralis (SpVIr). Furthermore, retrograde viral tracing from muscles that control orofacial actions shows that these premotor nuclei segregate their outputs. In the most dramatic case, both SpVO and SpVIr are premotor to forelimb and vibrissa muscles, while only SpVO is premotor to jaw muscles. Functional confirmation of the superimposed control by MCtx was obtained through selective optogenetic activation of corticobul

SUBMITTER: Mercer Lindsay N 

PROVIDER: S-EPMC7962749 | biostudies-literature | 2019 Nov

REPOSITORIES: biostudies-literature