Figure 4.

Long-term memory is rescued by PDE-4 inhibitor treatment in fragile X flies. (A) Long-term memory (4 days post training) was measured in WT and FS flies that were administered vehicle control food or drug treatments contained in the food. Memory Index (±the error) are plotted; Ns are indicated above each bar for all groups. The levels of significance are ^*p < 0.05; ^**p < 0.01; ^***p < 0.001, and are generated from comparisons of same genotype, same treatment between LTM trained and sham trained flies. Filled bars indicate WT males; open bars indicate FS males. Flies were raised on regular food and starting on the 1st day of adulthood placed on either vehicle control food containing DMSO vehicle or food supplemented with either 50 μM Rolipram (Roli) or 20 uM Ro-20-1724 (Ro-20). With vehicle treatment, FS males did not display long-term memory. FS flies treated with rolipram or R0-20-1724 did demonstrate long-term memory. WT flies treated with either vehicle, rolipram or Ro-20-1724 demonstrated long-term memory. (B) Rolipram rescues the olfactory-based long-term memory defect observed in dfmr1 mutants, but does not alter memory after massed training. Flies 1–3 days of age were fed Rolipram overnight before and after spaced training. Long-term memory of olfactory conditioning after spaced training was significantly improved in FS mutants after being administered rolipram. The levels of significance are indicated as follows: ^***p < 0.001. No effect was observed in WT controls.