BACKGROUND : We have established that activation of the tryptophan degrading enzyme indoleamine 2,3 dioxygenase ( IDO ) mediates the switch from cytokine-induced sickness behavior to depressive-like behavior .
O O O O O O O O O B-ChemicalEntity O O B-GeneOrGeneProduct I-GeneOrGeneProduct I-GeneOrGeneProduct O B-GeneOrGeneProduct O O O O O O O O O B-DiseaseOrPhenotypicFeature O O