Progressive changes in somatosensory cortical maps in 2 week old kittens following low thoracic (T12) spinal cord transection

The present study investigated the reorganization of the somatosensory cortex in kittens following T12 spinal cord transection at 2 weeks of age. Multiunit electrophysiological methods were used to map the somatosensory cortex of kittens at 3, 6, and 9 weeks after the transection. The entire reorganized cortical region was driven by substitute cutaneous inputs at 3 weeks after spinal cord transection. This level of cortical responsiveness remained the same throughout the other two time periods studied. Also, throughout the 9 weeks studied, the majority of the substitute inputs came from the trunk. A smaller percentage of the substitute inputs arose from the shoulder girdle and the forelimb region. A lack of somatotopic and topographic order was seen in the reorganized cortex of all experimental animals. Finally, trunk receptive fields displayed a wide variety of shapes, sizes and orientations not seen in the normal cortex