Fig. 8.

Simultaneous blockade of 3 excitatory receptor neuromodulators was insufficient to alter pulmonary ventilation (V̇_I; A) and breathing frequency (B) as indicated by the finding that unilateral dialysis into the ventral respiratory column during the day of a triple mixture of antagonist [5 mM atropine (ATR), 500 µM spantide (SPA), and 0.5 mM MDL 11939] had no effect on V̇_I or breathing frequency. The x-axis is time from start of dialysis. Open triangles are data when mock cerebral spinal fluid (mCSF) was dialyzed over the entire period, and circles are when the mixture was dialyzed during hour 2 of dialysis (closed squares and black line indicate period of cocktail dialysis). F and P are values from interaction term of two-way repeated measures ANOVA. mAChRs, muscarinic acetylcholine receptors.