Figure 3

cEPOR mice reveal improved synaptic short- and long-term plasticity. (A,B) Input-output curves of evoked EPSPs: The moderate right-shift of response amplitudes (A) and slopes (B) in cEPOR mice suggests slightly reduced basal excitability (WT n = 10, TG n = 10). (C,D) Short-term plasticity as tested by paired-pulse facilitation was markedly enhanced in cEPOR mice. The amplitude (C) and slope (D) of the second EPSP are normalized to the first EPSP of a given twin pulse. Plotted are the averages of 12 (wildtype) and 11 (cEPOR TG) slices. Error bars represent SEM and the level of significance of the changes observed is indicated. The sample responses shown in the inset (D) were elicited by 30 μA stimuli separated by 25 ms; stimulation artefacts are truncated. Baseline stimulation intensities (adjusted to obtain about half maximum fEPSP amplitudes) for stimulation in PPF and long-term potentiation (LTP) experiments differed only slightly among genotypes. On average, the chosen stimulation intensities were 50 μA for WT and 60 μA for transgenic slices. (E,F) Also, post tetanic potentiation (PTP) as well as LTP was more pronounced in cEPOR mice. LTP was induced at time 0; plotted are the normalized averages of 11 slices for each genotype. The sample responses in the inset (F) show EPSPs under baseline conditions, immediately after the LTP-inducing stimulus, that is the phase of PTP, and 60 minutes after stimulation. Responses were elicited by 60 μA stimuli, scaling is identical to panel D.