Fig. 1. Effects of intravenous anesthetics on the concentrations of 5-hydroxytryptamine (5-HT, A ) and 5-hydroxyindoleacetic acid (5-HIAA, B ) in dialysates from the striatum. Saline (0.7 ml/kg, ○)–, midazolam (5 mg/kg, Δ)–, propofol (60 mg/kg, •)–, and pentobarbital (15 mg/kg, ▴)–injected groups. Arrows represent administration of saline or intravenous anesthetics. Each value represents the mean ± SD (n = 9). Changes in 5-HIAA by intravenous anesthetics were significant: F = 4.682, P = 0.008 for the drug; F = 43.217, P < 0.001 for time; F = 14.136, P < 0.001 for the drug × time interaction. * P < 0.05, ** P < 0.01 as compared with each corresponding value in the saline group. + P < 0.05, ++ P < 0.01 as compared with each corresponding value in the pentobarbital group.