Transcutaneous auricular vagus nerve stimulation enhances structural and functional remodeling in sensorimotor networks following intracerebral hemorrhage in rats.

Abstract

Background: Intracerebral hemorrhage (ICH) leads to severe neurological deficits by disrupting brain structure and function, particularly in the sensorimotor cortex. Effective interventions to promote post-ICH brain remodeling remain limited. This study investigated the effects of transcutaneous auricular vagus nerve stimulation (taVNS) on structural and functional remodeling in the sensorimotor networks of rats with ICH, using multi-scale analyses spanning micro-, meso-, and macro-levels.

Methods: A rat model of left basal ganglia ICH was established, followed by taVNS intervention. Structural remodeling was assessed through histology, immunofluorescence, and transmission electron microscopy. Functional remodeling was evaluated using fractional amplitude of low-frequency fluctuations (fALFF) and degree centrality (DC) analyses.

Results: taVNS enhanced myelin repair and axonal remodeling, indicated by increased myelin basic protein (MBP) expression, reduced dephosphorylated neurofilament protein (SMI-32), and partial restoration of synaptic ultrastructure. Functional imaging showed significant longitudinal increases in zfALFF and zDC values in sensorimotor regions, including the primary and secondary motor cortices, which negatively correlated with modified neurological severity scores (mNSS).

Conclusion: taVNS promotes structural and functional remodeling in the sensorimotor cortex after ICH, offering a potential therapeutic strategy for neurological recovery.