Mouse barrel cortex functionally compensates for deprivation produced by neonatal lesion of whisker follicles

In the murine somatosensory pathway, the metabolic whisker map in barrel cortex derived with the autoradiographic deoxyglucose method is spatially in register with the morphological whisker map represented by the barrels. The barrel cortex of adult mice, in which we had removed three whisker follicles from the middle row of whiskers shortly after birth, contained a disorganized zone surrounded by enlarged barrels with partially disrupted borders. With the fully quantitative autoradiographic deoxyglucose method, we investigated in barrel cortex of such mice the magnitude and the pattern of metabolic responses evoked by the deflection of whiskers. Most remarkably, the simultaneous deflection of six whiskers neighbouring the lesion activated not only the territory of the corresponding barrels, but also the unspecifiable area intercalated between the clearly identified barrels. This metabolic whisker map, unpredictable from the morphological 'barrel' map, may reflect a functional compensation for the deficit in input.