Bioelectric remodeling of the blastemal signaling center after cyclic mechano-stimulation during appendage regeneration

Objective Cyclic mechano-stimulation has recently been implicated in accelerating functional tissue restoration. We investigated the underlying mechanisms of this intervention in a vertebrate limb-regeneration model, focusing on its influence over the bioelectric dynamics of the distal blastemal signaling center, a critical regulator of patterning. Methods One hundred sessions of controlled flexion–extension were delivered to regenerating limb stumps from nine adult specimens. Each animal underwent up to 12 sessions across a four-week period. Extracellular bioelectric field potentials were recorded from the dorsal-lateral and ventral regions of the blastema immediately before and after stimulation using implanted microelectrode arrays. We quantified both acute and sustained effects on the bioelectric spectra. Periodic activity was characterized by the dominant spectral frequency and its associated power, whereas aperiodic activity was assessed by estimating the 1⁄f exponent of the power spectrum. Results Acute changes in bioelectric parameters were minimal. In contrast, repeated stimulation produced a progressive rise in both power and the 1⁄f exponent within the dorsal-lateral blastema, indicating heightened bioelectric fluctuation and signal complexity. No comparable alteration was detected in the ventral compartment. Conclusion Prolonged cyclic mechano-stimulation induces region-specific bioelectric remodeling in the blastemal signaling center. The absence of immediate effects yet pronounced long-term modulation underscores the importance of sustained mechanical cues in steering regenerative bioelectric states. Significance These findings reveal a mechanistic link between rehabilitative mechanical loading and bioelectric patterning during appendage regeneration, suggesting new strategies to harness endogenous electrical cues for improved regenerative outcomes.