Fig. 3. TRAP labeling shows no increase in the numbers of C1 whisker-responsive neurons in the peri-infarct cortex 2 months after stroke.
a Schematic of TRAP labeling approach. Two months after stroke targeting the C1 barrel, cFos-CreERT2:Ai9 mice were subjected to whisker trimming (all whiskers except C1) and then allowed to explore an enriched environment, using only the right-sided C1 whisker for 6 h, immediately following injection of 4-OHT (50 mg/kg in corn oil). b Top: representative images (across n = 6 sham and n = 4 stroke mice) of activity-dependent TRAP labeling in S1BF. Putative C1 whisker-responsive neurons are labeled in red (tdTom); DAPI counterstain. Example regions for quantification are outlined in yellow surrounding either the intact C1 barrel in sham control mice (left panel) or the infarct core in stroke mice (right panel). Note the large density of cFos-expressing (TRAP+) neurons in the C1 barrel in sham control mice. Scale bar = 200 μm. Bottom: high magnification of L4 TRAP-labeled cells surrounding the intact C1 barrel in sham control mice (left panel) or the infarct core in stroke mice (right panel). Scale bar = 50 μm. c Quantification of the total number of TRAP+ neurons in the peri-infarct cortex (stroke group, red, n = 4) or surround barrels (sham group, gray, n = 6), separated by cortical layers. No significant differences were found using a two-way ANOVA for effects of group (p = 0.736), layer (p = 0.828), or group × layer (p = 0.995). Bars show mean ± s.e.m., with data points for individual mice overlaid.