MOUSE BARREL CORTEX FUNCTIONALLY COMPENSATES FOR DEPRIVATION PRODUCEDBY NEONATAL LESION OF WHISKER FOLLICLES

In the murine somatosensory pathway, the metabolic whisker map in barr el cortex derived with the autoradiographic deoxyglucose method is spa tially in register with the morphological whisker map represented by t he barrels. The barrel cortex of adult mice, in which we had removed t hree whisker follicles from the middle row of whiskers shortly after b irth, contained a disorganized zone surrounded by enlarged barrels wit h partially disrupted borders. With the fully quantitative autoradiogr aphic deoxyglucose method, we investigated in barrel cortex of such mi ce the magnitude and the pattern of metabolic responses evoked by the deflection of whiskers. Most remarkably, the simultaneous deflection o f six whiskers neighbouring the lesion activated not only the territor y of the corresponding barrels, but also the unspecifiable area interc alated 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.