Chronic social stress induces peripheral and central immune activation, blunted mesolimbic dopamine function, and reduced reward-directed behaviour in mice

Publication date: February 2018Source: Neurobiology of Stress, Volume 8Author(s): Giorgio Bergamini, Jonas Mechtersheimer, Damiano Azzinnari, Hannes Sigrist, Michaela Buerge, Robert Dallmann, Robert Freije, Afroditi Kouraki, Jolanta Opacka-Juffry, Erich Seifritz, Boris Ferger, Tobias Suter, Christopher R. PryceAbstractPsychosocial stress is a major risk factor for depression, stress leads to peripheral and central immune activation, immune activation is associated with blunted dopamine (DA) neural function, DA function underlies reward interest, and reduced reward interest is a core symptom of depression. These states might be inter-independent in a complex causal pathway. Whilst animal-model evidence exists for some specific steps in the pathway, there is currently no animal model in which it has been demonstrated that social stress leads to each of these immune, neural and behavioural states. Such a model would provide important existential evidence for the complex pathway and would enable the study of causality and mediating mechanisms at specific steps in the pathway. Therefore, in the present mouse study we investigated for effects of 15-day resident-intruder chronic social stress (CSS) on each of these states. Relative to controls, CSS mice exhibited higher spleen levels of granulocytes, inflammatory monocytes and T helper 17 cells; plasma levels of inducible nitric oxide synthase; and liver expression of genes encoding kynurenine pathway enzymes. CSS led in the ventr...

Source: Neurobiology of Stress - July 5, 2018 Category: Neuroscience Source Type: research