Experimental approach
IDO inhibitor 1-MT was directly injected into PrL and IL of depressive rats induced by ICV-STZ, respectively. Depressive- and anxiety-behaviors were evaluated in forced swim test, sucrose preference test, novelty-suppressed feeding test, novel object recognition test and open field test. HPLC‒MS/MS detected kynurenine metabolites, ELISA detected cytokines, Western blot examined protein expression and Golgi staining assessed synaptic plasticity. Immunofluorescence staining was used to observe the expression and morphology of glial cells.