Drugs were bath applied for 3–5 min. Responses were recorded continuously in control and during drug application (Figures 3(b) and 4(b) ). Baclofen and CGP 55845 were obtained from Sigma-Aldrich (St Louis, MO), gabazine (SR95531) was obtained from Abcam (Cambridge, UK). Data were analyzed off-line using pClamp10 software. Analysis of drug effects on synaptic responses was performed on EPSCs recorded 2–3 min after the start of drug application. EPSC peak amplitudes were determined in a constant 2 ms window. Mean peak amplitudes and paired-pulse ratios (PPRs) were calculated from 5–6 averaged traces in the different experimental conditions. The total charge transfer of EPSCs evoked by a stimulation train of four stimuli was determined by taking the area under the traces between the baseline time point immediately before the first EPSC and the time point at which the fourth EPSC recovered to baseline.
Graphs were obtained using Sigmaplot 11 (Systat software, San Jose, CA) and statistical analysis was performed using GraphPad (GraphPad software, San Diego, CA). Data were expressed as mean ± SEM and differences were considered significant for p < 0.05.
Graphs were obtained using Sigmaplot 11 (Systat software, San Jose, CA) and statistical analysis was performed using GraphPad (GraphPad software, San Diego, CA). Data were expressed as mean ± SEM and differences were considered significant for p < 0.05.