Figure 3.
Depolarization does not induce DOPr activity in morphine-naive PAG neurons. A, Representative pharmacologically isolated mIPSC traces (Vh =-60 mV) recorded in normal ACSF ([K+]o = 2.5 mm) and after superfusions of high [K+]o ACSF (+15 mm), DELT (1 μm), Met-enkephalin (ME; 10 μm), and washout (Wash) of Met-enkephalin. B, Time course of mIPSCs for the neuron shown in A. Elevation of [K+]o increased the rate of mIPSCs. Application of DELT in the presence of 17.5 mm [K+]o does not affect the mIPSC rate, but subsequent application of Met-enkephalin reversibly reduces the mIPSC rate. C, Histogram illustrating the effects of high [K+]o ACSF and applications of DELT (1 μm) and Met-enkephalin (10 μm) on the mIPSC rate and amplitude (ampl.).