Fig. 1

Young Adult DKI mice demonstrate no learning and memory deficit at 3 months. A 3‐month‐old WT (blue), Prnp^−/− (red), DKI (green) and DKI; Prnp^−/− (purple) mice completed the MWM to investigate the age of spatial memory deficit. Latency is defined as the average time of 4 trials to find a hidden platform across 6 acquisition sessions. No significant difference was observed in the time to reach the platform during the final acquisition session in any genotype compared to DKI. Data are graphed as mean ± SEM, analyzed by two‐way ANOVA with Dunnett’s multiple comparisons test, P > 0.05, n = 20 for WT, n = 18 for Prnp^−/−, n = 18 for DKI, and n = 21 for DKI; Prnp^−/−. B 24 h after completing the final acquisition session, all 4 genotypes completed a probe trial. The percent permanence is defined as the fraction of 60 s spent in the quadrant where the platform was during acquisition trials. No significant difference was observed in the percent permanence in any genotype compared to DKI. Data are graphed as mean ± SEM, analyzed by two‐way ANOVA with Dunnett’s multiple comparisons test, P > 0.05, n = 20 for WT, n = 18 for Prnp^−/−, n = 18 for DKI, and n = 21 for DKI; Prnp^−/−. C 3-month-old WT, Prnp^−/−, DKI and DKI; Prnp^−/− mice completed the NOR test. All 4 genotypes preferred to interact with the novel object compared to the familiar object. Data are graphed as mean ± SEM, analyzed by two‐way ANOVA with Sidak's multiple comparisons test, ** P < 0.01, ***P < 0.001, ****P < 0.0001, n = 14 for WT, n = 18 for Prnp^−/−, n = 16 for DKI, and n = 20 for DKI; Prnp^−/−