although the concentration of circulating 5-hydroxytryptamine was markedly decreased , the concentrations of 5-hydroxytryptamine and noradrenaline in the brain were not affected . p-chlorophenylalanine , an inhibitor of 5-hydroxytryptamine synthesis , decreased the 5-hydroxytryptamine content of brain to very low values in both the deficient and control animals , whereas the noradrenaline contents were not appreciably affected .
C0423896
content
C0006104
brain