CHARACTERIZATION OF PERILESIONAL MOTOR CORTICAL ACTIVITY DURING THE CHRONIC PHASE OF ISCHEMIC STROKE

Ischemic stroke induces profound alterations in cortical network activity, both locally and across brain regions. However, how neuronal dynamics in the perilesional areas are reorganized after stroke remains partially understood. In this study, we investigated local field potential (LFP) activity in the caudal forelimb area (CFA), a motor cortical region adjacent to the ischemic core affecting primary and secondary somatosensory cortices, using a mouse model of distal middle cerebral artery occlusion (dMCAO). Electrophysiological recordings were obtained using single-channel electrodes implanted in the CFA of awake mice at 30 days post-stroke, the chronic phase of the disease. Animals were head-fixed but allowed to freely move on a running wheel. Behavioural state classification was achieved through video-based motion analysis, enabling segmentation of neural activity into resting, movement, and pre- and post-motion epochs, without the use of external sensors. LFP signals were analyzed by separating periodic oscillatory components from aperiodic activity, quantifying bands power as well as the offset and exponent of the aperiodic component. This analysis provided insight into state dependent and movement-related alterations in perilesional cortical dynamics after stroke. Ongoing work expands this framework to longitudinal multichannel recordings across cortical layers, both during wheel-locomotion and during a skilled motor task (water grasping), allowing investigation of task-related activity. Post-mortem histological analysis of lesion extent will further enable correlation between structural damage and electrophysiological alterations. Together, this multimodal approach aims to characterize the reorganization of motor cortical circuits after ischemic stroke and to link neural dynamics with spontaneous and goal-directed motor behaviour.