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. Author manuscript; available in PMC: 2017 Jul 7.
Published in final edited form as: Neurobiol Learn Mem. 2016 Jul 11;138:135–144. doi: 10.1016/j.nlm.2016.07.008

Fig. 3.

Fig. 3

Increased PKMζ persists in dorsal hippocampus 1 month after spaced active place avoidance training. (A) Inset above, schematic representation of training protocol consisting of two 8-trial training sessions spaced 1 week apart with 30-day memory retention testing. Left, representative 5 min paths before training, at the end of training, and during retention testing with the shock off 1 month after spaced training. Control animals are placed in the apparatus without conditioning. Right, mean ± SEM, measure of active place avoidance behavior 1 month after spaced training. There is a main effect of treatment (control, trained) (F1,10 = 125.56, P < 0.0001), training phase (pretraining, training, retention) (F2,20 = 37.63, P < 0.0001), as well as their interaction (F2,20 = 34.03, P < 0.0001). The retention performance differs (*, significant post hoc Tukey HSD test, n’s = 6, P < 0.01). (B) Above, representative immunoblots; below, mean ± SEM, showing increases in dorsal hippocampal PKMζ 1 month after spaced training (n’s = 6, t10 = 2.38, P < 0.05). (C and D) After 1 month, memory induced by a single 8-trial massed training session fades, and the amount of PKMζ in dorsal hippocampus is indistinguishable from that of untrained controls. (C) Left, representative 5 min paths before training, at the end of training, and during retention testing with the shock off 1 month after massed training. Control rats are placed in the apparatus without conditioning. Right, mean ± SEM measure of active place avoidance behavior 1 month after massed training. There is a main effect of treatment (control, trained) (F1,13 = 31.46, P < 0.0001), training phase (pretraining, training, retention) (F2,26 = 40.71, P < 0.0001), and interaction between treatment and training phase (pretraining, training, retention) (F2,26 = 35.41, P < 0.0001). There is no significant difference between the two groups on 1-month retention testing (control, n = 8, trained, n = 7, P = 0.99; n.s., no significance). (D) Immunoblots shows no significant difference in the amount of dorsal hippocampal PKMζ between control and 1 month after massed training. Above, representative immunoblots. Below, mean ± SEM (control, n = 8, trained, n = 7, t13 = 0.87, P = 0.40).