Figure 10.

BDNF cKO attenuated CPP to cocaine. A, Wild-type control and BDNF cKO mice exhibited no significant unconditioned preference in each chamber during pretest (n = 9–11 for each group; p > 0.05). B, Mice received saline (0.9% NaCl, i.p.) and cocaine (15 mg/kg) place conditioning once daily for 6 d. CPP was tested 24 h after the last conditioning. BDNF cKO significantly decreased the CPP score in cocaine-conditioned mice (**p < 0.01) but did not affect the CPP score in saline-conditioned mice (p > 0.05). C, D, Same as in A, B, wild-type control and BDNF cKO mice underwent cocaine conditioning. There was no unconditioned place preference during pretest (n = 9 or 10 for each group; p > 0.05; C). The mice were pretreated with vehicle or DHF (5 mg/kg, i.p.) before each saline or cocaine conditioning. CPP was significantly attenuated in vehicle-pretreated BDNF cKO mice compared with vehicle-pretreated wild-type mice (***p < 0.001), whereas DHF pretreatment significantly increased cocaine CPP in BDNF cKO mice (***p < 0.001), but not in control mice (p > 0.05).