Fig. 6

Mild bTBI caused deficits in basic synaptic properties and short-term plasticity. a Assessment of the effect of mild blast forces on long-term potentiation (LTP) in rats at 1, 3, 7 and 21 day(s) after bTBI exposure, as well as in controls. The graph shows the time-course of the field excitatory postsynaptic potential (fEPSP) slopes before and after high frequency stimulation (HSF) in percentage from the baseline. Insets show representative traces of recordings from control slices (α: baseline, β: post-tetanic potentiation (PTP) phase, γ: LTP phase). Arrowhead indicates the time point of HFS. b Summary of PTP changes in response to HFS shows a significant reduction at 7 and 21 days post-bTBI (*p < 0.05, **p < 0.01, vs. control, one-way ANOVA, Newman-Keuls post hoc). c Paired pulse ratio (PPR) at baseline and during PTP phase in slices from rats at 7 and 21 days post-bTBI, as well as in controls (*p < 0.05, **p < 0.01, vs. baseline, Wilcoxon test, ^#p < 0.05, vs. control, Mann-Whitney test). d Input-output curves from fEPSP slopes against normalized fiber volley amplitudes. Connecting lines show a non-linear regression using a polynomial quadratic function for each group. Inset shows representative traces of recordings from control slices at different stimulation intensities. e Paired pulse facilitation (PPF) at different inter-stimulus intervals shows a significant difference at 21 days post-bTBI (**p < 0.01, two-way ANOVA, Tukey’s post hoc). All data are presented as mean ± SEM; n = 7–9 slices from 2 to 4 individual rats