Unilateral dialysis during the day of 100μM DAMGO (n=9, filled circles) did not significantly (P ≥0.758) alter ventilation (V̇I, panel A), breathing frequency (f, panel B) or tidal volume (VT, panel C) compared to dialysis of mCSF alone (n=7, open circles). Data are means ± SE. The x Axis is time from start of 180 minutes of dialysis. As indicated by the black line, 100μM DAMGO was dialyzed between 60 and 120 minutes. The values shown during and after DAMGO dialyses are the percent of the last 15 minutes prior to DAMGO dialyses. F and P values are the interaction term obtained from two-way repeated measures ANOVA using time and dose as factors. Note the trend of a transient reduction in V̇I and f over the last 30 minutes of DAMGO dialysis.