(A–C) Statistical correlation of protein expression levels with behavioral data in shocked and non-shocked mice: intensities of the different symptoms of the murine PTSD-like syndrome, i.e. conditioned fear, generalized and the acoustic startle response (ASR), were plotted against the relative day-60 protein expression levels (% of no shock) of synapsin Ia–b/IIa (A), synaptophysin (B) and homer 1b/c (C) of both shocked and control mice (i.e. each cloud of dots comprises both shocked and mock-treated mice). Pearson correlation coefficients (“r”) were calculated and a two-tailed student’s t-test was performed (“p”), n = 12 (batch PTSD I and II) for synapsin Ia–b/IIa and homer 1b/c, n = 6 (batch PTSD I only) for synaptophysin (synapsin: conditioned fear: r = −0.630, p = 0.001; generalized fear: r = −0.624, p = 0.003; hyperarousal: r = −0.200, p = 0.371; synaptophysin: conditioned fear: r = 0.657, p = 0.020; generalized fear: r = −0.621, p = 0.031; hyperarousal: r = −0.048, p = 0.881; homer 1b/c: conditioned fear: r = −0.626, p = 0.001; generalized fear: r = −0.413, p = 0.098; hyperarousal: r = −0.075, p = 0.737).