Mapping plasticity in the forepaw digit barrel subfield of rat brains using functional MRI

►High resolution fMRI with 300 micron isotropic resolution was used to map the topographic organization of the forepaw barrel subfield in layer IV of rat primary somatosensory cortex. ►By alternating electrical stimulation of the 2nd (D2) and 4th (D4) digits, BOLD activation in layer IV of the barrel subfields could be distinguished with differential analysis. ►Two and a half months after the amputation of the 3rd digit in baby rats, the overlapping area between D2 and D4 representations was increased, indicating the representation previously associated with the ablated digit is now associated with that of nearby digits.