Auricular Transcutaneous Vagus Nerve Stimulation Enhances Post-Stroke Neurological and Cognitive Recovery in Mice by Suppressing Ferroptosis Through α7 Nicotinic Acetylcholine Receptor Activation

Aims: Ferroptosis plays a critical role in stroke pathophysiology, yet its dynamics during recovery remain unclear. This study aimed to investigate the evolution of ferroptosis throughout post-stroke recovery and evaluate auricular transcutaneous vagus nerve stimulation (atVNS) as a therapeutic intervention, focusing on the involvement of α7 nicotinic acetylcholine receptor (α7nAChR)-mediated mechanisms. Methods: Using a middle cerebral artery occlusion (MCAO) mouse model, we examined ferroptosis-related protein expression (GPX4, ACSL4, TfR) and iron levels across acute to chronic recovery phases. The therapeutic effects of atVNS were evaluated through the assessment of ferroptosis markers, neurogenesis, angiogenesis, cognitive function, and neuroinflammation. α7nAChR knockout mice were used to investigate the receptor's role in atVNS-mediated recovery. Results: We observed sustained alterations in ferroptosis markers and iron levels throughout post-stroke recovery. atVNS treatment reduced ferroptosis progression by modulating GPX4 and ACSL4 expression, enhanced neurogenesis and angiogenesis, improved cognitive recovery, and reduced neuroinflammation. These beneficial effects were absent in α7nAChR knockout mice, while atVNS increased neuronal α7nAChR expression in wild-type mice. Conclusions: This study reveals the persistent involvement of ferroptosis in stroke recovery and demonstrates that atVNS provides comprehensive neuroprotection through α7nAChR-dependent mechanisms. These findings establish atVNS as a promising noninvasive therapeutic approach for stroke recovery and highlight α7nAChR signaling as a potential therapeutic target.