Fig. 3.

CA3-CA1 synapses in Prnp^ZH3/ZH3 mice show enhanced excitability. a Schematic representation of electrodes implanted in mouse dorsal hippocampus. Two stimulation electrodes are implanted in the Schaffer collateral pathway in the CA3 region and two recording electrodes in the CA1 stratum radiatum. b Effects of the paired-pulse stimulation of the Schaffer collateral pathway at increasing inter-stimulus intervals (10, 20, 40, 100, 200, 500 ms). Data are presented as the percentage of increase of fEPSP2 in relation to fEPSP1 (fEPSP2/fEPSP1 × 100). c The inset illustrates representative examples of fEPSPs (averaged 5 times) evoked by paired pulses (40 ms of inter-pulse interval) of similar intensities (2 × Threshold; ≈ 0.2 mA) in Prnp^+/+ and Prnp^ZH3/ZH3 mice. d,e Input/output curves of fEPSPs (V/s) in CA1 after the presentation of paired-pulses of increasing intensities in the CA3 area (0.02 mA to 0.4 mA) of Prnp^+/+ (d) and Prnp^ZH3/ZH3 (e) mice. f,g The insets show representative recordings of fEPSPs evoked in Prnp^+/+ (f) and Prnp^ZH3/ZH3 (g) mice by paired pulses (40 ms of inter-pulse interval) of similar intensities (0.1 mA, 0.2 mA, and 0.3 mA). h Paired-pulse ratio (fEPSP2 / fEPSP1 × 100) of data illustrated in d, e, and i area under the curve (a.u.) of PP ratio from 0.24 mA to 0.4 intensities. Data are presented as mean ± S.E.M; p < 0.05, **p < 0.01, and ***p < 0.001, two-way ANOVA + Bonferroni’s multiple comparisons test. Source data and individual data values are available in Additional file 10