Russo, S.

serotonin serotonergic function drive system behavior withdrawal depression fatigue brain activity response state dopamine effect serotonergic function serotonin function avoidance journal anxiety stimulation study threat disorder deakin stress hypothesis / brain treatment psychiatry stimuli control tryptophan environment reward serotonergic systems processing theory inhibition animal evidence research personality oxytocin dominance mechanism psychopharmacology neuromodulator projection withdrawal drive cognition level phasic vigilance decrease activation serotonergic system reactivity increase aggression antidepressant dorsal monkey aversive raphe result tonic dopaminergic stimulation environments american journal fluence interaction 427–436 nucleus tryptophan depletion patient exercise review contrast university