Figure 1: CREB/CRTC is required for LTM maintenance but not for LTM formation. | Nature Communications

Figure 1: CREB/CRTC is required for LTM maintenance but not for LTM formation.

From: Shifting transcriptional machinery is required for long-term memory maintenance and modification in Drosophila mushroom bodies

Figure 1

(a–d) Knockdown of CRTC impairs 4-day LTM maintenance. Wild-type flies (+/+) or the flies carrying the indicated UAS transgenes were crossed with MBsw and their progeny were tested as shown to test 4-day LTM maintenance (a, from left to right, n=10, 10, 10, 10, 10, 10, 8 and 8), LTM formation (b, from left to right, n=7, 8, 8, 8, 8, 10, 8 and 8) and 7-day LTM maintenance (c, from left to right, n=10, 12, 10, 8, 8 and 8; d, from left to right, n=11, 10, 10, 8, 8 and 8)). *P<0.05, **P<0.01 and ***P<0.001 by Student’s t test. (e–n) Subcellular localization of CRTC in the MBs from 1 to 3 days, but not 7 days after spaced training. UAS-CRTC-HA flies were crossed with a MB GAL driver MB247. CRTC-HA was stained using anti-HA antibodies (green) and the nuclei were stained by TO-PRO-3 iodide (magenta). The images are representative of four to five experimental replicates, which are quantified in g–n. (e,h,k) The MB cell bodies, Kenyon cells (KC) and the dendritic region calyx (CA) are indicated by white dotted lines. The naive control flies were sampled at the same age after eclosion as the spaced trained flies. Scale bars, 10 μm. (f,i,l) Magnified view of the yellow squared area in e,h and k, respectively. White arrow heads indicate nuclear translocation of CRTC. Scale bars, 2 μm. (g,j,m) Median CRTC-HA nuclear intensities are increased at 1 and 3 days, but not 7 days, after spaced training. The individual nuclear CRTC-HA signal intensities were normalized to those in the calyx. The median nuclear CRTC-HA signal intensities in each brain was obtained and the averaged medians were shown (from left to right in g–m, n=4, 4, 5, 4, 5 and 4). *P<0.05 by Mann–Whitney U-test. (n) Median number of the nuclei showing more CRTC-HA intensities than the calyx (naive from left to right, n=5, 4, 5 and 5; spaced training from left to right t, n=4, 4, 4 and 5). A two-way analysis of variance of the data indicates significant effect of time (P<0.001) and treatment (naive or spaced; P<0.001), but not in interaction between them (P>0.66). **P<0.01 by Bonferroni testing.

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