Modulation of Reciprocal Inhibition and Excitation between Antagonist Motor Pools by Foxp2-Expressing V1 Interneurons and Renshaw Cells
Poster at Society for Neuroscience Annual Meeting (SfN 2026) , Washington, DC, USA
Abstract summary
This poster examines how Foxp2-expressing V1-derived Ia inhibitory interneurons (Foxp2-V1s) and Renshaw cells (RCs) shape reciprocal responses between antagonist motor pools. In decerebrate mice, we recorded electromyographic activity from lateral gastrocnemius and tibialis anterior muscles while high-frequency vibration of the gastrocnemius preferentially recruited Ia afferents.
The vibration elicited weak reciprocal excitation in tibialis anterior, rather than pure inhibition. Ablating Foxp2-V1s increased this excitation, while ablating RCs reduced it. These findings suggest that Foxp2-V1s suppress reciprocal excitatory drive and that RC-mediated inhibition of IaINs may permit or amplify that drive. The results point to a balance between Ia inhibitory signaling and parallel excitatory pathways in shaping reciprocal motor output.
Authors: Andrew E. Worthy, William M. McCallum, Briella M. Lucadamo, Jenima Charles, Samuel J. Sober, and Francisco J. Alvarez.
Presentation details
- Session: PSTR141, Motor Units, Kinematics, and EMG
- Time: 8:00 AM–12:00 PM
- Presentation number: PSTR141.03
- Poster board: BB12
- Abstract control number: 5812
Pre-SFN Motor Symposium
I’m registered to attend the symposium at Georgetown University on Friday, November 13, 2026.
Support
NIH-NINDS grants R01-NS047357 and R21-NS106209; T32-NS096050; 2026 Animal Research Tomorrow 3R Award.