DEEP-BRAIN NEUROMODULATION BY TEMPORAL INTERFERENCE STIMULATION ENHANCES SENSORIMOTOR PLASTICITY AFTER EXPERIMENTAL STROKE

Background: Recovery after ischemic stroke depends on adaptive reorganization within distributed sensorimotor networks. However, conventional non-invasive brain stimulation methods have limited access to deep neural circuits implicated in post-stroke plasticity. Transcranial temporal interference stimulation (tTIS) enables non-invasive modulation of deeper brain regions through the interaction of high-frequency electrical fields, offering a novel approach for investigating post-ischemic neural plasticity. Methods: A rat model of middle cerebral artery occlusion (MCAO) was used to examine the effects of tTIS on post-stroke functional recovery. Animals were assigned to sham, MCAO, or MCAO+tTIS groups. tTIS was delivered beginning on the day of ischemia (1 mA, intermittent theta-burst pattern, 30 minutes/day for five days). Longitudinal behavioral assessments were performed to quantify neurological impairment, motor coordination, somatosensory processing, and exploratory behavior. Results: Stroke induced pronounced deficits in motor and sensory domains. tTIS-treated animals exhibited accelerated recovery of motor coordination and somatosensory responsiveness compared with untreated stroke controls. Restoration of tactile processing approached sham levels, suggesting enhanced functional reorganization within sensorimotor circuits. Cognitive measures showed modest improvement, accompanied by reduced anxiety-like behavior. Conclusion: These findings suggest that tTIS facilitates post-ischemic sensorimotor plasticity through modulation of deep neural networks, highlighting its potential as a translational tool for studying circuit-level mechanisms of recovery after stroke.