Fig. 4.

The effect of unilateral dialysis of 50 mM atropine into the ventral respiratory column (VRC) appears state-independent as shown by the finding that the mock cerebral spinal fluid (mCSF) effluent concentration of serotonin (5-HT; A), γ-aminobutyric acid (GABA; B), and glycine (GLY; C) did not differ (P > 0.05) between day and night studies even though the goats were in nonrapid eye movement for extended periods at night. The 1st and 2nd bars for each hour represent day and night studies, respectively. The shaded gray represents when 50 mM atropine (ATR) was dialyzed. F and P values are from two-way repeated measures ANOVA comparing day and night values *P < 0.05 between treatment groups, †P < 0.05 vs. hour 1.