(A) Detection of Mef2a and Mef2d transcripts by in situ hybridization in littermate CTL and Mef2a/d
DKO (DKO) mice. Arrow indicates hippocampus. (B) Expression level of MEF2 transcription factors in the hippocampus of Mef2a/d
DKO mice as detected by quantitative RT-PCR. RNA was isolated from the hippocampus of 4 week old animals (n=3/genotype), and then expression determined by quantitative PCR. The fold change in RNA was calculated using the comparative Ct method, normalizing to GAPDH as a control. (C) Mef2a/d
DKO mice exhibit impaired motor coordination as assessed by falling off the accelerating rotarod faster than littermate CTLs (F1,7=27.64, P<0.05; CTL, n=8; Mef2a/d
DKO, n=10), posthoc analysis demonstrated that trial numbers 3–8 were significantly different between the Mef2a/d
DKO and CTL mice. (D) Mef2a/d
DKO mice show normal associative learning, as assessed by context- and cue-dependent fear conditioning (CTL, n=8; Mef2a/d
DKO, n=10). (E) Representative images of Golgi-stained CA1 pyramidal neurons and a bar graph comparing the number of dendritic spines per 10 µm length of dendrite from littermate CTL and Mef2a/d
DKO mice (n=31 dendritic segments from 31 neurons of two CTL mice and n=68 dendritic segments from 68 neurons of four Mef2a/d
DKO mice). (F) CA1 LTP induction and maintenance is normal in DKO mice (CTL, n=3; Mef2a/d
DKO, n=3). (G) Input-output relations are normal in Mef2a/d
DKO mice (CTL, n=4; Mef2a/d
DKO, n=4; solid lines indicate lines of best fit.). (H) Paired-pulse facilitation is increased in Mef2a/d
DKO mice at Inter-Stimulus Interval 20, 30, 50, 100, 200 and 400 (mS) compared to littermate CTLs, suggesting decreased presynaptic release probability (CTL, n=8; Mef2a/d
DKO, n=7). All data is shown as mean ± SEM.