Research Paper Volume 15, Issue 13 pp 5990—6010

Figure 5. Memory retention after strong encoding and non-rewarded reactivation in aging. (A) Rats received a strong encoding trial (3 rewards, filled circle), a reactivation trial with a non-rewarded sandwell (open circle) at 6 hours later, and a non-rewarded probe trial at another 18 hours later. Exploration in a novel box was introduced or omitted at 30 min after reactivation. (B) In rats without prior training, the percentage of correct digging was not different from chance (dashed line) without novelty (one-sample t-test, t₉ = 0.41, p = 0.69, attrition of 2 rats) and was significantly above chance with novelty (one-sample t-test, t₉ = 3.21, p = 0.01). No difference was observed between the conditions (paired t-test, t₉ = 1.91, p = 0.09; Bonferroni’s multiple comparison test p = 0.18). (C) In rats with prior training, the percentage of correct digging was not different from chance (dashed line) without novelty (one-sample t-test, t₁₂ = 0.18, p = 0.86) and was significantly above chance with novelty (one-sample t-test, t₁₁ = 6.01, p < 0.001). The condition difference was significant (paired t-test, t₁₁ = 2.84, p = 0.02; Bonferroni’s multiple comparison test p = 0.014). (D) Rats received a strong encoding trial (filled circle), exploration in a novel box at 6.5 hours later, and a non-rewarded probe trial at another 17.5 hours later. (E) The percentage of correct digging was not above chance in either group (No prior training: one-sample t-test, t₉ = 0.09, p = 0.93; Priorly trained: one-sample t-test, t₁₁ = 0.31, p = 0.76). Data are presented as mean ± SD. ^*p < 0.05, ^***p < 0.005.