Figure 4

AP bursting-induced reductions in mEPSC IEI are transcription-dependent. (A) Stimulation protocol used to block gene transcription and to induce action potential bursting (see Methods). Actinomycin D (8 μM) was applied 15 minutes prior to bicuculline and left on the cells for 2 hours after bicuculline washout. The time line indicates the period over which mEPSCs were recorded after washout of bicuculline. (B) Shown are the mean values of mEPSC IEI (left), mEPSC amplitude (centre) and whole-cell AMPA response (right) recorded from cells treated with actinomycin D followed by a 15 minute treatment with either vehicle or bicuculline. Bursting activity was assessed at the beginning of each recording. Cell numbers in each group are indicated in the mEPSC IEI histogram. Asterisks indicate significant differences with respect to bicuculline treated, action potential bursting cells. (C) The IEI data shown in B is separated into 3 groups to illustrate the time course of its modulation by bicuculline after actinomycin D treatment. The numbers within columns represent n of cells per group. ** p < 0.01