Layer-specific sensory processing impairment in the primary somatosensory cortex after motor cortex infarction

Abstract

Primary motor cortex (M1) infarction occasionally causes sensory impairment. Because sensory signal plays an important role in motor control, sensory impairment compromises recovery and rehabilitation from motor disability. Despite the importance of sensory-motor integration for rehabilitation after M1 infarction, the neural mechanism of the sensory impairment is poorly understood. We show that the sensory processing in the primary somatosensory cortex (S1) was impaired in the acute phase of M1 infarction and recovered in a layer-specific manner in the subacute phase. This layer dependent recovery process and the anatomical connection pattern from M1 to S1 suggested the functional connectivity from M1 to S1 plays a key role in the impairment of sensory processing in S1. The simulation study demonstrated that the loss of inhibition from M1 to S1 in the acute phase of M1 infarction could cause the sensory processing impairment in S1, and the complementation of inhibition could recover the temporal coding. Taken together, we revealed how focal stroke of M1 alters cortical network activity of sensory processing, in which inhibitory input from M1 to S1 may be involved.