Changes in whole-cell holding current evoked by baclofen were measured at a holding potential (Vhold) of −60 mV. The holding current, input resistance (Rin), and series resistance (RA) values were monitored throughout these experiments by tracking responses to periodic (0.2 Hz) voltage steps (−5 mV, 800 ms). Only experiments with stable (<20% variation) and low series resistances (<20 MΩ) were included in the final data set. The GABABR antagonist CGP54626 (2 μM) was used to verify the receptor-dependence of baclofen-evoked responses. sIPSCs were measured over a 2-3 min period at Vhold = −70 mV, in the presence of kynurenic acid (2 mM). sEPSCs were measured over 2-3 min period at Vhold = −80 mV, in the presence of picrotoxin (100 μM). All data were low-pass filtered at 2 kHz, digitized at 10 kHz, and analyzed using pCLAMP v.9 software (Molecular Devices).
