Varied ionic currents underlie functional diversity of hypoglossal motoneurons innervating the superior longitudinalis and genioglossus tongue muscles.

ABSTRACT: Hypoglossal motoneurons (XIIMNs) control tongue movement, which must be precisely coordinated for communication, swallowing and respiration. We previously found that XIIMNs innervating intrinsic and extrinsic tongue muscles exhibit diverse firing properties. Here we investigate the mechanisms behind functional differences of XIIMNs that control the superior longitudinalis (SL) and genioglossus (GG) muscles, which retract and protrude the tongue, respectively. We hypothesized that varied ionic currents drive muscle-specific firing properties in XIIMNs. We obtained whole-cell patch-clamp recordings from retrogradely labelled SL and GG XIIMNs obtained from male and female neonatal rats. SL and GG XIIMNs exhibited distinct firing patterns, and SL XIIMNs had higher intrinsic excitability than G

SUBMITTER: Frazure M 

PROVIDER: S-EPMC12671391 | biostudies-literature | 2025 May

REPOSITORIES: biostudies-literature