food intake , growth , plasma and brain amino acid , and brain serotonin and 5-hydroxyindole-3-acetic acid ( 5-hiaa ) concentrations were measured in rats fed low protein diets containing disproportionate amounts of large neutral amino acids ( lnaa ) devoid of tryptophan or histidine ( tryptophan or histidine imbalance ) .
C0006104
brain
C0086045
concentrations