Figure 2

EphA7 knockdown rats impairs long-term potentiation and learning.

(a) Basic excitability parameters of the dentate gyrus neuronal population (field recordings). Intrinsic excitability of the neurons (i.e. population spike; top) and synaptic excitability (i.e. EPSP slope; bottom) are enhanced with increasing stimulation amplitude applied from the perforant path. EphA7 knockdown group: n = 12; control group: n = 11. No significant differences were found between groups (p > 0.05). Error bars, S.E.M. (b) Alterations in population spikes following frequency-dependent inhibition (FDI; stimulation frequency was increased from 0.1 to 1 Hz), paired-pulse inhibition (PPI; interval between the two pulses was 15 ms) and commissural inhibition (COMM; commissural pulse preceded perforant path pulse with 15/30 ms). Data are expressed as percentage of baseline measurements, averaged for 5 (PPI and COMM) or 10 (FDI) pulses. Knockdown group: n = 12; control group: n = 11. No significant differences were found between groups (p > 0.05). Error bars: S.E.M. (c) LTP following high frequency stimulation. Potentiation of the EPSP slope (top) and population spike (bottom) following theta burst stimulation, expressed as percentage of baseline measurements. The knockdown group (n = 9) exhibits reduced slope of the EPSP in comparison to the control group (n = 8). Arrows indicate time of high frequency stimulation. *p < 0.05; error bars, S.E.M. (d) Example traces of field recordings from a control rat before (left) and after (right) theta burst stimulation. Calibration: 5 ms/2 mV. (e) Avoidance responses per session in the two way shuttle avoidance task. Control group (n = 11) improves performance in the second session, while knockdown group (n = 12) shows no such improvement. *p < 0.01; error bars: S.E.M. ANOVA.