Functional MRI Demonstrates a Novel Role for Callosal Function to Protect Deprived Barrel Cortex from Adjacent Cortical Takeover by Plasiticy in Rodent Brain

Xin Yu¹, Stephen Dodd¹, Alan Koretsky¹

Despite extensive studies of intracortical plasticity due to sensory deprivation or overuse, the effect of callosal inputs from the opposite hemisphere on cortical reorganization is seldom studied. Here, we studied the effect of transcallosal functional changes from the normal barrel cortex (BC) to the deprived BC on the takeover of the deprived BC by adjacent forepaw somatosensory cortex (FP-S1). Functional MRI at 300um isotropic resolution detected FP-S1expansion toward the deprived BC only if the callosal inputs from the normal BC were removed by ablation of this cortex. This result indicates a specific role played by transcallosal plasticity for functional recovery.