The effect of progesterone treatment in aged animals. Comparison of post-surgery survival according to treatment/surgery in aged C57 Bl/6 mice (A). Mortality data expressed using the Kaplan-Meier curve and analysed using the Mantel-Haenszel log-rank test revealed no significant difference between groups in % of surviving animals (P = 0.5266). Body mass gain following surgery in aged C57 Bl/6 mice (B) at 24 h post-MCAO found no difference in body mass gain between progesterone and vehicle treated animals groups (P = 0.8903). Neurological score was assessed in aged C57/Bl6 at 24 h post-MCAO (C) no difference was found between treatment groups. Individual data points are shown for body mass and neurological score.