Research Paper Volume 15, Issue 13 pp 6031—6072

Figure 8. Basal synaptic transmission of stratum radiatum in area CA1 is affected in an experience- and MSK1-dependent manner. (A) The RM-ANOVA on the fEPSP Input/Output profile in the Adult groups with a within-factor as stimulus strength (20 to 300 μA) gave a significant effect (F(6,492) = 958.85, p < 0.0001) and an interaction of stimulus strength x Genotype: F(6,492) = 10.09, p < 0.0001 but no significant interaction of stimulus strength x Housing, nor stimulus strength x Genotype x Housing. There was also a significant effect of Genotype (F(1,82) = 13.07, p = 0.001), but no significant interaction Genotype x Housing nor Housing alone. A comparison of the fibre volley amplitude across a subset of experiments (10–12 pathways from 7–9 slices and from 7–9 mice) where the fiber volley was measurable at 300 μA (inset, bottom right, data points offset for clarity) showed no significant (ns) effect of Genotype, Housing, or Genotype x Housing across groups. (B) The RM-ANOVA on the paired-pulse facilitation in the Adult groups with inter-pulse interval (50–350 ms) as a within-factor variable gave only a significant effect of interval (F(6,432) = 1229.1, p < 0.0001) but not of Genotype or Housing. (C) In the Aged groups there was a significant effect of stimulus strength (F(6,360) = 787.75, p < 0.0001) and an interaction between stimulus strength x genotype (F(6,360) = 7.18, p < 0.0001). The between effects analysis revealed a significant effect of genotype (F(1,60) = 28.22, p < 0.0001) and an interaction Genotype x Housing (F(1,60) = 8.26, p = 0.006). The simple main effect analysis revealed a significant difference between standard-housed and enriched WT mice (F(1,60) = 5.44, p = 0.023) and between standard-housed WT and MSK1 KD mice (F(1,60) = 33.51, p < 0.0001). A comparison of the fibre volley amplitude across a subset of experiments (10–14 pathways from 6–9 slices and from 6–9 mice) showed no significant (ns) effect of Genotype, Housing, or Genotype x Housing across groups. (D) In the analysis of the paired-pulse facilitation data, there was only a significant effect of interval (F(6,348) = 614.28, p < 0.0001), but not of Genotype or Housing. Data are presented as mean ± SEM.