Figure 8.

Formalin-induced expression of spinal cord Fos and primary afferent ATF3 in male BDNF-cKO mice. A, B, Two hours after formalin, control (Ctrl) and tamoxifen (Tam)-treated (cKO) mice showed a comparable increase of Fos immunoreactivity in the spinal dorsal horn ipsilateral to the injected paw. C, D, Both groups also showed equivalent ATF3 induction in L4/5 DRGs 2 d after the formalin injection, consistent with formalin producing peripheral axotomy. Data are mean ± SEM. Statistical significance was determined by Student’s t test. Numbers of animals are indicated on graphs. Scale bars = 50 μm (A) and 100 µm (C).