Endogenous automatic nerve discharge promotes nerve repair: an optimized animal model

Area of Science:

• Neuroscience
• Regenerative Medicine
• Surgical Innovation

Background:

• Exogenous electrical stimulation aids nerve regeneration.
• Endogenous nerve discharge effects on regeneration are complex, potentially hindered by scar compression.
• Previous studies indicated mixed outcomes for endogenous nerve discharge at different postoperative times.

Purpose of the Study:

• To investigate the impact of phrenic, intercostal, and thoracodorsal nerve transfers on musculocutaneous nerve regeneration.
• To develop and validate rat models that mitigate scar compression effects on nerve repair.
• To assess early-stage nerve regeneration using electrophysiological and histological parameters.

Main Methods:

• Four rat models were created: control (musculocutaneous nerve repair), and three nerve transfer groups (phrenic, intercostal, thoracodorsal) with sural nerve autografts.
• Regeneration was evaluated via electrophysiology, muscle tension, wet weight, cross-sectional area, and myelinated fiber counts.
• Assessments were performed at 1, 2, and 3 months postoperatively.

Main Results:

• At 1 month, phrenic and intercostal nerve groups showed significantly higher compound muscle action potential amplitude and distal myelinated nerve fiber counts compared to controls.
• The phrenic and intercostal nerve groups exhibited lower neural degeneration rates in nerve grafts than the thoracodorsal nerve group.
• No significant differences were observed between groups at 2 and 3 months postoperatively.

Conclusions:

• Phrenic and intercostal nerves positively influence early-stage nerve regeneration.
• The optimized animal model effectively prevents scar compression-induced inhibition of nerve recovery.
• Nerve transfers can be a viable strategy to enhance nerve regeneration outcomes.