Interaction between citalopram and omega-3 fatty acids on anxiety and depression behaviors and maintaining the stability of brain pyramidal neurons in mice

•Induction of acute and chronic restraint stress caused anxiogenic- and depressive-like effects.•These stresses reduced live cells but enhanced dark cells in the prefrontal cortex and hippocampus.•Alone and combination treatment with citalopram and omega-3 caused anxiolytic and antidepressant effects.•This combination therapy raised live cells but reduced dark cells in the prefrontal cortex and hippocampus.•There is an interaction between citalopram and omega-3 on the induction of anxiolytic and antidepressant effects.•Citalopram and omega-3 increased the stability of cells in the prefrontal cortex and hippocampus.