text:  Hipp PDE9 Tg-, rep4 Hippocampus wild type mouse after 28 days of chronic sc PF-04447943 infusion age: 4 months; strain: B6SJLF1 (F1 cross between C57Bl/6 and SJL); genotype/variation: Tg- (non-transgenic WT littermates); tissue: Hippocampus; treated with: PF-04447943 (PDE9A-inhibitor) for 28 days