Differential tolerance to dietary amino acid-induced changes in aggressive behavior and locomotor activity in mice.
Male albino mice were maintained on a semisynthetic 12% casein protein diet for 2 weeks, then switched to diets modified by the addition of a 4% L-amino acid supplement (L-tyrosine, L-phenylalanine, and L-tryptophan) or 4% casein (control). Territorial=induced aggressive behavior increased following 1 week on the amino acid supplements, especially after tyrosine, but an apparent tolerance developed to these effects after 5 weeks on the amino acid supplements. Locomotor activity also increased following 1 week on the supplements, most notably after phenylalanine alone or in combination with tyrosine, and these effects tended to persist after 5 weeks on the supplements. Endogenous whole brain levels of dopamine, norepinephrine, serotonin, 5-hydroxyindoleacetic acid, tyrosine, phenylalanine, and tryptophan showed no tolerance to increased concentrations of brain catecholamines and indoleamines over the 5-week period, and no clear relation between the concentrations of these monoamines and the behavioral changes.
D000374:Aggression / Q000187:drug effects*; D000596:Amino Acids / Q000378:metabolism / Q000494:pharmacology*; D000818:Animals; D001923:Brain Chemistry / Q000187:drug effects; D002395:Catecholamines / Q000378:metabolism; D004032:Diet; D004361:Drug Tolerance; D006801:Humans; D008297:Male; D051379:Mice; D009043:Motor Activity / Q000187:drug effects*; D013997:Time Factors
D000596:Amino Acids; D002395:Catecholamines