Postsynaptic deregulation in GAP-43 heterozygous mouse barrel cortex.
A distribution of dendrites was studied in mouse barrel field after a neonatal unilateral partial lesion of vibrissal follicles using anti-MAP-2 immunohistochemistry. The effect of a neonatal vibrissal follicles removal was studied in adult mice: barrels corresponding to intact follicles were enlarged whereas those representing removed follicles had not developed. MAP-2 immunopositive profiles were considered to be dendritic clusters and their packing density (a number per unit area) was calculated in an enlarged barrel and compared to a control barrel in a contralateral hemisphere. A decrease in the packing density of large dendritic clusters (area over 10 microns 2), presumably arising from layer V, was observed in an enlarged barrel in comparison to its control counterpart. This result may indicate a rearrangement of a dendritic pattern in mouse barrel field after a selective neonatal lesion of vibrissal follicles.