A. For recording population spikes induced by 4-AP. A recording electrode was positioned in CA1 pyramidal cell layer. The orthodromic response was first evoked to test the integrity of the slice. After 20 min of acclimatization in the interface chamber under 4-AP superfusion, we started recording baseline levels (4-AP). Next, two doses of either drug were administered subsequently at 20 min intervals.
B. Example of an orthodromic evoked potential. The arrow indicates the position of the stimulus artifact and the references used to calculate the evoked potential amplitude (ΔV) and delay (Δt) are also shown.
C. Examples of epileptiform discharges induced by 4-AP and increase in population spikes after superfusion of capsaicin (CIN)
D. Mean ± SEM RMS µV showing a dose related increase in power induce by CIN. * p < 0.05, repeated measures ANOVA followed by post-hoc tests.
E. Examples of epileptiform discharges induced by 4-AP and decrease in population spikes after superfusion of capsazepine (CZP).
F. Mean ± SEM RMS µV showing a dose related decrease in power induced by CZP. ** p < 0.001 * p < 0.05, compared with control or other doses, repeated measures ANOVA followed by post-hoc tests.