Figure 5.

Average PPR at 30 ms ISI in different experimental conditions. (A) Average PPR at 30 ms ISI in PV+/+ (n = 12) and in PV−/− mice (n = 19). The interneurons were stimulated by using an extracellular stimulation. The PPRs are significantly different (asterisks). (B) Average PPR at 30 ms ISI in paired recordings. The interneurons were stimulated by depolarizing steps in whole-cell voltage-clamp configuration. The presynaptic recording solution contained different concentrations of EGTA or Mg²⁺. Significant differences can be observed between PV+/+ and PV−/− for two different presynaptic solutions (dots and triangles). Both in PV+/+ and in PV−/− mice, the PPR is significantly reduced by increasing the concentration of EGTA (open and filled squares).