Figure 6.
Repeated cocaine exposure alters the presynaptic and postsynaptic effects of CRF in VTA neurons. A, Example saline and cocaine AMPAR mEPSC recordings at −70 mV at baseline and after CRF from the same VTA neuron, respectively. B, C, Averaged AMPAR mEPSCs from 4 min baseline before CRF and from the last 4 min of the 10 min CRF exposure, showing that CRF did not alter the mEPSC amplitude in saline- or cocaine-treated mice (B) but enhanced the mEPSC frequency significantly only in cocaine-treated mice (C). D, E, Representative cumulative probability plots of mEPSC amplitude (D) (saline baseline, 200 mEPSCs; saline CRF, 280 mEPSCs; cocaine baseline, 240 mEPSCs; cocaine CRF, 450 mEPSCs) and frequency (E) (saline baseline, 360 mEPSCs; saline CRF, 420 mEPSCs; cocaine baseline, 280 mEPSCs; cocaine CRF, 500 mEPSCs) from individual cells from each group. Note the leftward shift and increased slope with CRF application after chronic cocaine in E. *p < 0.05, CRF change versus baseline (t test).