treatment with antibiotics (Fig. 6a - F(1,37) = 7.308; p = 0.01), but there was no main effect of cocaine (F(1,37) = 0.6841; p = 0.41) or significant treatment interaction (F(1,37) = 2.004; p = 0.17). When levels of Ntrk2 were examined from the same samples there was a significant main effect of antibiotics (Fig. 6b - F(1,38) = 10.31; p = 0.003), cocaine F(1,38) = 4.1; p = 0.05), and an antibiotics x cocaine interaction (F(1,38) = 5.377; p = 0.03). Interestingly, Holm-Sidak post-hoc analysis shows that this is driven by the Antibiotics+Cocaine group which was significantly different from all other groups in this analysis. These results suggest that depletion of the gut microbiota with oral antibiotics substantially alters BDNF-TrkB signaling in NAc, changes that may well be playing a role in the behavioral changes we see in antibiotic-treated mice.
