Table 1.
Differential expression of miRNA after LTP induction.
| Study | Organism | Preparation | LTP induction | Time-points post-LTP induction | Identification of candidate miRNA | Control | Criteria for differential expression | Differentially expressed miRNA determined by RT-qPCR validation |
|---|---|---|---|---|---|---|---|---|
| Joilin et al. (2014) | 4–6 months old Sprague Dawley rat | Dentate gyrus; LTP in vivo, un-anesthetized | HFS to PP-GC synapses | 20 min, 5 and 24 h | Affymetrix microarray: 65/6,703 miRNA had FC ≥ 1.15; n = 4 | Unstimulated hemisphere (within animal) | FC ≥ 1.15; p < 0.05: paired t-test | miR-34a-5p down-regulated at 20 min (FC = 0.44 ± 0.07; n = 8) and 5 h (FC = 0.53 ± 0.16; n = 5); back to baseline at 24 h miR-132-3p down-regulated at 20 min (FC = 0.37 ± 0.11; n = 8); back to baseline at 5 h and 24 h |
| Lee et al. (2012a) | 4–5 weeks old Sprague Dawley rat | Hippocampal slice | Chemical LTP | 30, 60, 120 min | Agilent microarray: 5/287 miRNA had FC ≥ 1.5 at at least one time-point; n = 1 | Slices that did not undergo LTP induction | FC ≥ 1.5; p < 0.05: one-way ANOVA and LSD post hoc | miR-188-5p up-regulated at 60 min (FC = 1.75 ± 0.3; n = 3); no regulation at 30 min or 120 min. Four other miRNA (unidentified) were not regulated at any time-points |
| Pai et al. (2014) | Adult Sprague Dawley rat | Dentate gyrus; LTP in vivo, anesthetized. Total lysate and Ago2 IP examined | HFS to PP-GC synapses | 30, 120 min | miRCURY microarray: 44/376 miRNA differentially expressed (p < 0.05: Student’s t-test with Dunn–Bonferroni correction); n = 3 | Unstimulated hemisphere (within animal) | p < 0.05; one-way ANOVA | Total lysate: miR-384-3p, miR-29b-3p, miR-219a-5p, miR-592-5p, miR-20a-5p, let-7f-5p, miR-338-3p, miR-212-3p, miR-34a-5p, miR-19a-3p, miR-326-3p up-regulated at 30 min; miR-223-3p down-regulated at 30 min. Ago2 IP: miR-384-3p, miR-29b-3p, miR-219a-5p, miR-592-5p, miR-20a-5p, let-7f-5p, miR-338-3p, miR-330-5p, miR-223-3p, miR-34a-5p, miR-19a-3p up-regulated at 30 min; miR-212-3p down-regulated at 30 min |
| Park and Tang (2009) | 7–8 weeks old C57/BL6 mice | Hippocampal slice | Chemical LTP | 0, 15, 30, 60, 120 min | GenoExplorer microarray: 55/237 miRNA had mean FC over all time-points ≥ 2; n = 1 | Slices that did not undergo LTP induction | FC ≥ 2 | miR-181b-5p not regulated at any time-point (n = 10); miR-128a-3p not regulated at any time-point (n = 10) |
| Ryan et al. (2012) | 4–6 months old Sprague Dawley rat | Dentate gyrus; LTP in vivo, un-anesthetized | HFS to PP-GC synapses | 5 h | IPA network analysis: miRNA identified as hubs in LTP-related gene networks | Unstimulated hemisphere (within animal) | FC ≥ 1.15; p < 0.05: paired t-test | miR-34a-5p down-regulated (FC = 0.53 ± 0.16; n = 5); miR-24-3p down-regulated (FC = 0.59 ± 0.12; n = 9) |
| Wibrand et al. (2010) | Adult Sprague Dawley rat | Dentate gyrus; LTP in vivo, anesthetized | HFS to PP-GC synapses | 10, 120 min | LC Sciences microarray: 21/237 miRNA had FC ≥ 1.2 at 120 min; n = 2 | Unstimulated hemisphere (within animal) | FC ≥ 1.20; p < 0.05: t-test | miR-132-3p up-regulated at 120 min (FC = 1.38; n = 8); miR-212-3p up-regulated at 120 min (FC = 1.26; n = 8); miR-219a-5p down-regulated at 120 min (FC = 0.68; n = 8). None of the three miRNA were regulated at 10 min (n = 5) |
| Wibrand et al. (2012) | Adult Sprague Dawley rat | Dentate gyrus; LTP in vivo, anesthetized | HFS to PP-GC synapses | 30, 120 min | Arc-targeting miRNA | Unstimulated hemisphere (within animal) | FC ≥ 1.20; p < 0.05: t-test | miR-132-3p up-regulated at 120 min (FC = ∼1.6; n = 5); not regulated at 30 min. No regulation of miR-19a-3p, miR-34a-5p, miR-326-3p, miR-193a-3p at 30 min or 120 min |
Ago2 IP, Argonaute 2 immunoprecipitates; FC, fold change; GC, granule cell; h, hour; HFS, high frequency stimulation; IPA, Ingenuity Pathway Analysis; LSD, least significant difference; LTP, long-term potentiation; min, minute; PP, perforant path; RT-qPCR, real time-quantitative polymerase chain reaction. Data are presented as mean ± SEM.