Expansion of contralesional sensory representation to ipsilesional hindlimb stimulation in acute phase of ischemic stroke in rat model

Stroke could result in both structural and functional impairments. Sensory remapping is believed to play a special role in cortical plasticity, which contributes to the recovery after ischemic stroke. Previous studies using imaging and electrophysiological methods have found that sensory representations after stroke can remap not only to the surrounding areas, but also to remote areas. Based on a rodent photothrombotic stroke model using optical intrinsic signal (OIS) imaging, the present study attempts to investigate the remapping of sensory representation in contralesional cortex to ipsilesional hindlimb stimulation. Quantitative analysis revealed an overall expansion of hindlimb representation in contralesional cortex after stroke. Moreover, results indicated that hindlimb representation became less correlated to different stimulation intensity in contrast to the previous positive correlation before stroke. We speculate that diaschisis in the acute stage of stroke might account for such a change in contralesional sensory representation.