Projections of the common fur of the muzzle upon the cortical area for mystacial vibrissae in rats dewhiskered since birth.

In normal adult rats, the mystacial vibrissae and the common fur of the snout project at different loci on the SI cortex. The surface area of the normal fur projection is 0.8 mm2, whereas the vibrissa field amounts to 3-4 mm2. In rats dewhiskered since birth, the vibrissa area can still be identified through the projections from ipsilateral vibrissae (undamaged side). It is shown that in the absence of the vibrissae since birth, the vibrissa area, and this alone, is invaded by projections from the contralateral fur (damaged side).