Figure 3.

Changes in 130 pS channel properties after chronic morphine treatment. For all figures, the dose of chronic morphine was 2 mg/kg/h for 6 days. (A) Recordings with 10 μM morphine in the patch pipette from a control cell (Top) and from a cell from a rat treated with morphine (Bottom), at two time scales. (B) Fractional open probability P_o at resting potential as a function of morphine concentration, n = 6–8 recordings. *, P < 0.01 vs. drug-naive (10 μM). **, P < 0.05 vs. chronic morphine (10 μM). Burst duration (C) and interburst interval (D) as a function of morphine treatment. Drug-naive, 10 μM, P < 0.05 vs. each other condition, by Kruskal–Wallis one-way ANOVA on ranks.