Fig. 1.

Impaired activity-dependent short-term synaptic plasticity in dentate granule cells of Shn2 knockout mice. a Medical perforant path (MPP) synaptic potentials evoked at the stimulus intensities of 1.5, 2, 3, 4 and 5 V in wild-type (+/+) and Shn2 knockout (−/−) mice. Scale bar: 10 ms, 1 mV. b Dependence of fiber volley amplitude (left) and EPSP slope (center) on stimulus intensity, and the relationship between fiber volley and EPSP (right). The mutant showed smaller fiber volley amplitude (repeated measure two-way ANOVA: genotype effect, F_1,28 = 7.995, P = 0.0086, n = 15 each; Sidak’s test: *P < 0.05, ***P < 0.001). c Reduced paired-pulse depression in the mutant mice (repeated measure two-way ANOVA: genotype effect, F_1,12 = 22.15, P = 0.0005, n = 7 each; Sidak’s test: ****P < 0.0001). Sample traces show EPSPs evoked by paired stimulation at the 50 ms interval. Scale bar: 20 ms, 0.2 mV. d Significant reduction in the magnitude of synaptic depression during 5 Hz stimulation in the mutant mice (t₈ = 2.651, P = 0.0292, n = 5 each), but no significant change at 1 Hz (n = 5 each). Sixty pulses were delivered at 1 or 5 Hz, and the depression ratio was measured for the last 15 pulses. Sample traces are averages of 15 consecutive EPSPs during baseline and 5 Hz stimulation. Scale bar: 10 ms, 0.4 mV. e Reduced short-term potentiation after high-frequency tetanic stimulation in the mutant mice (repeated measure two-way ANOVA: genotype × time interaction, F_7,63 = 11.69, P < 0.0001; Sidak’s test: **P = 0.0051; +/+: n = 5, −/− n = 6). Tetanic stimulation (100 Hz, 0.5 s repeated three times) was delivered at time 0. EPSP slopes were averaged at 5 min bin for statistical analysis. Sample traces are averages of 15 consecutive EPSPs during baseline, immediately after tetanus and 35 to 40 min after tetanus. Scale bar: 10 ms, 0.5 mV