Figure 4

Granule cells of adult Rbfox3^−/− mice exhibit normal long-term potentiation (LTP) but exhibit a deficit in long-term depression (LTD).

(a) Schematic of recording configuration in hippocampal slices for LTP in the medial perforant path (mPP) of the dentate gyrus. Basal synaptic transmission from wild-type (WT) and Rbfox3^−/− (KO) mice was recorded as shown (a) with varying stimulus intensities (0-20 V) plotted against (b), the presynaptic fiber volley amplitudes and (c), the slope of the field excitatory post-synaptic potential (fEPSP) (WT, n = 7 slices, 3 mice; KO, n = 7 slices, 3 mice). Two-way repeated measures ANOVA with Holm-Sidak post hoc comparison, *P < 0.05. (d) Fiber volley amplitude plotted against the slope of fEPSP. (WT, n = 7 slices, 3 mice; KO, n = 7 slices, 3 mice). Two-way repeated measures ANOVA with Holm-Sidak post hoc comparison, *P < 0.05. Representative traces with varying stimulus intensities from WT and KO mice are shown in (a). Scale bars represent 0.5 mV and 20 ms. (e) Analysis of paired-pulse ratio (PPR) at different interpulse intervals. Representative traces from WT and KO mice are from 50 ms inter-pulse intervals. Scale bars represent 0.25 mV and 10 ms (WT, n = 7 slices, 3 mice; KO, n = 7 slices, 3 mice). Two-way repeated measures ANOVA with Holm-Sidak post hoc comparison, *P < 0.05. (f) Representative waveforms and averaged data of LTP induced with theta burst stimulation (TBS). Bar graph shows comparable LTP in WT and KO mice (WT, n = 10 slices, 5 mice; KO, n = 10 slices, 5 mice). Scale bars represent 10 ms and 0.5 mV. (g) Representative waveforms and averaged data of LTD following low frequency stimulation (LFS). Bar graph shows lower LTD for KO than for WT mice. (WT, n = 14 slices, 5 mice; KO, n = 14 slices, 5 mice). Scale bars represent 10 ms and 0.5 mV. Two-way repeated measures ANOVA with Holm-Sidak post hoc comparison, *P < 0.05; Student’s t-test, two tailed, *P < 0.05. All data are the mean ± s.e.m.