Effects of rosiglitazone on CA1-Schaffer collateral field evoked potentials (fEPSPs) and CA1 pyramidal cell miniature excitatory postsynaptic currents (mEPSC).

(A) Representative traces of fEPSPs before (black color) and after application of 1,5,10μM rosiglitazone with/without 20μM GW9662 treatment for 30 minutes (red color). (B) The slope of first fEPSPs were suppressed significantly by 5 and 10μM rosiglitazone. (C) Cotreatment with 20μM GW9662 partially reversed the suppression of fEPSP slope induced by 10μM rosiglitazone. (D) Quantification of fEPSP slope after rosiglitazone/GW9662 treatment for 30 minutes. (E) Application of 10μM rosilglitazone significantly increased pair-pulse ratio on CA1-Schaffer collateral fEPSPs, which indicates rosiglitazone significantly suppresses presynaptic neurotransmitter release. This effect can be completely reverse by pretreatment with 20μM GW9662. (F) Miniature EPSCs recorded on CA1 pyrimidal cells. Application of 10μM rosiglitazone significantly suppressed mEPSC frequency but not amplitude. Cumulative probability of mEPSC inter-event interval (P<0.001 by Kolmogorov–Smirnov test) and mEPSC amplitude (P = 0.18 by K-S test) from the representative trace of mEPSC were illustrated. *P<0.05 **P<0.01.