(A,B) Histamine (10 μg/μl), (C,D) chloroquine (CQ; 4 μg/μl), or (E,F) β-alanine (20 μg/μl) was injected into the nape of the neck in saline- or DTX-treated CGRPα-DTR+/− mice (male and female data plotted separately). Scratching bouts were measured for 30 min in 5 min blocks. (Insets) Total number of scratching bouts. n=10–26 mice/treatment group. T tests were used to compare responses at each time point between saline- and DTX-treated mice. *p<0.05, **p<0.005, ***p<0.0005.