Journal: eLife
Article Title: Role of protein synthesis and DNA methylation in the consolidation and maintenance of long-term memory in Aplysia
doi: 10.7554/eLife.18299
Figure Lengend Snippet: ( A ) Experimental protocol. The times at which the pretests, training, posttests, and drug/vehicle injections occurred are shown relative to the end of the last training session. The time of the intrahemocoelic injection of either RG108 or vehicle is indicated by the red arrow. After the 48-h posttest, animals in the 5XTrained-RG-5XTrained group received a second round of full sensitization training (five bouts of electrical tail shocks). ( B ) Sensitization retraining produced LTS in animals following erasure of LTM by RG108. There were four experimental groups: Control-Veh group ( n = 6), 5XTrained-Veh group ( n = 6), 5XTrained-RG group ( n = 4), and 5XTrained-RG-5XTrained group ( n = 6). A repeated-measures ANOVA indicated that the group x time interaction was significant (F [9,54] = 61.4, p < 0.0001). Subsequent one-way ANOVAs indicated that the overall differences among the four groups at 24 h, 48 h and 72 h were highly significant (24 h, F [3,18] = 33.3, p < 0.0001; 48 h, F [3,18] = 70.7, p < 0.0001; and 72 h, F [3,18] = 54.9, p < 0.0001). SNK posthoc tests performed on the 24-h data revealed that the initial training produced significant sensitization in the 5XTrained-Veh group (mean duration of the SWR = 50.8 ± 6.1 s), 5XTrained-RG group (mean duration of the SWR = 57.8 ± 2.3 s), and 5XTrained-RG-5XTrained group (mean duration of the SWR = 54.2 ± 5.8 s) compared with Control-Veh group (mean duration of the SWR = 1.2 ± 0.2 s; p < 0.001 for each comparison). The SWR of 5XTrained-Veh group also exhibited sensitization at 48 h (mean duration = 49.2 ± 5.2 s) and 72 h (mean duration = 45.2 ± 5.6 s) compared with the Control-Veh group (48 h, mean duration = 1.2 ± 0.2 s, p < 0.001; and 72 h, mean duration = 1.2 ± 0.2 s, p < 0.001). Sensitization memory was significantly disrupted at 48 h in both the 5XTrained-RG (mean SWR = 1.3 ± 0.3 s) and 5XTrained-RG-5XTrained (mean SWR = 2.2 ± 0.7 s) groups by the RG108 injection immediately after the 24-h posttest (p > 0.05 for the comparisons with the Control-Veh group). Retraining after the 48-h posttest reestablished full LTM. The mean duration of the SWR in the 5XTrained-RG-5XTrained group at 72 h (55.8 ± 4.2 s) was significantly greater than that for the Control-Veh group (mean duration = 1.2 ± 0.2 s, p < 0.001), as well as for the 5XTrained-RG group at 72 h (2.5 ± 1.0 s, p < 0.001). Asterisks, comparisons of the 5XTrained-Veh, 5XTrained-RG, and 5XTrained-RG-5XTrained groups with the Control-Veh group at 24 h; comparisons of the 5XTrained-Veh group with the Control-Veh, 5XTrained-RG, and 5XTrained-RG-5XTrained groups at 48 h; and comparison of the 5XTrained-Veh group with the Control-Veh and 5XTrained-RG groups at 72 h. Plus signs , comparison of the 5XTrained-RG-5XTrained group with the 5XTrained-RG group at 72 h. DOI: http://dx.doi.org/10.7554/eLife.18299.012
Article Snippet: The DNA methyltransferase (DNMT) inhibitors RG108 (Sigma, St Louis, MO) and 5-azadeoxycytidine (5-aza; EMD Millipore, Billerica, MA) were dissolved in DMSO to a concentration of 25 mM to make a stock solution.
Techniques: Injection, Produced, Control, Comparison