Fig. 5. (A) Progesterone (P4) production in preovulatory follicle granulosa cells following treatment with brain-derived neurotrophic factor (BDNF), k252a (100nmoll^-1), BDNF (50ngml^-1) plus the Trk (the high-affinity neurotrophin receptor of brain-derived neurotrophic factor) kinase activity inhibitor k252a or vehicle (control) for 18h following overnight preplating. Levels of progesterone are expressed as fold difference compared with the control. Values are means + S.E.M. (N=4 or 5 replicate experiments). ^a,bP<0.05; *P<0.05 for BDNF at 50ngml^-1 compared with the control, as determined by a post-hoc paired t-test. (B) Progesterone production in preovulatory follicle granulosa cells following treatment with BDNF (50ngml^-1), phorbol 12-myristate-13-acetate (PMA; 167nmoll^-1), BDNF plus PMA or vehicle (control) for 18h after overnight preplating. Levels of progesterone, expressed as fold difference compared with control cells, are not different among the three treatment groups. Values are means + S.E.M. (N=3 replicate experiments). *P<0.025 compared with the control, as determined by a post-hoc two-tail paired t-test.