Figure 7.

Pruritogen and formalin responsiveness in BDNF-cKO mice. A, Tamoxifen-treated cKO mice responded normally to injections of acute pruritogens including SLIGRL, chloroquine, endothelin-1, and TSLP. B, Female mice showed statistically elevated responses to histamine compared to vehicle-injected control animals, but the increase disappeared after tamoxifen, i.e., after BDNF deletion. C, Female tamoxifen-treated cKO mice did not respond differently from corn oil-injected controls during any of the three phases of the formalin test. D, Male BDNF cKO mice showed a large, highly significant decrease in their responses, but only during the second phase of the formalin test. E, Despite the dramatic reduction in behavior during the second phase of the formalin test, male cKO mice nevertheless developed significant mechanical allodynia 24 h after the formalin injection equivalent to that recorded in the control mice. Data are mean ± SEM. For A, C, D, statistical significance was determined by multiple t tests with Bonferroni correction for multiple comparisons. For B, statistical significance was determined by two-way ANOVA with Bonferroni correction for multiple comparisons. For E, statistical significance was determined by Student’s t test; *p < 0.05, ****p < 0.0001. Numbers of animals are indicated on graphs.