Figure 5. Ccr5+/- mice display accelerated experience dependent plasticity.
(A) Recording locations plotted on a standard barrel field map. The barrel shaded dark grey indicates the principal barrel for the spared whisker. The color of each circle represents the average response to D1 whisker stimulation (spikes per 50 stimulations) for cells in L2/3. Deprived Ccr5+/- mice showed greater proportion of penetrations responding strongly to D1 stimulation (WT: control vs deprived, p>0.99;Ccr5+/-: control vs deprived, p=0.0019, binomial test). (B) Vibrissae dominance histograms. Vibrissae dominance is calculated as D1/(PW + D1) and sorted into 10 bins (see Materials and methods). In WT mice, there is very little shift in the dominance histogram after 7 days of deprivation (n = 14). (C) The vibrissae dominance histogram shows a substantial shift right toward D1 dominance in the D1-spared Ccr5+/- mice (blue) compared with undeprived Ccr5+/- mice (red) (n = 24; p<0.01, Student’s t-test). (D) The value of the response to D1 stimulation is plotted against the same L2/3 cell’s response to principal whisker (PW) stimulation for mice subject to 7 days deprivation. A large number of Ccr5+/- (but not WT) cells lie above the unity line. (E) The average weighted vibrissae dominance index (WVDI) is plotted against deprivation period for WT and Ccr5+/- mice. Naïve WT and Ccr5+/- mice do not exhibit differences in their vibrissae dominance, however after 7 days deprivation there is an increase in WVDI in Ccr5+/- mice but not in WT mice (7-day WT vs Ccr5+/- mice: p=0.0030, ANOVA, Bonferroni post-tests). Error bars indicate SEM.