2DG and CO double-labeled sections through 5 portions of the V neuraxis in 2 P7 mouselings, one subjected to the passive D4 whisker deflection paradigm (left micrographs), the other to active D4 whisker deflection (right micrographs). Each panel has a corresponding higher magnification image to the immediate right of it to more readily discern 2DG label in/around the D4 module. a,a’. Left SpVc. Clusters of silver grains including heavily labeled cells are visible in the passive D4 and other whisker modules (barrelettes). b,b’. Left SpVi. Heavily labeled D4 patches can be seen in both animals. c,c’. Left PrV. The D4 patch is labeled only in the passive case. d,d’. Right VPM nucleus of the thalamus showing barreloids. D4 modules are labeled in both passive and active deflection. e,e’. The 9-barrel array in the right SI cortex. Passive and active deflection both activated the D4 and many surrounding barrels, a region of the SI cortex wider than that activated in adult animals. Also note the small cluster of heavily labeled cells near the center of the D4 barrel in e’. Calibration bars of 100 µm and 50 µm apply to all panel pairs at lower and higher magnifications, respectively. d=dorsal, m= medial, l= lateral, a=anterior.