Effects of social defeat stress on dopamine D2 receptor isoforms and proteins involved in intracellular trafficking

Abstract

BackgroundChronic social defeat stress induces depression and anxiety-like behaviors in rodents and also responsible for differentiating defeated animals into stress susceptible and resilient groups. The present study investigated the effects of social defeat stress on a variety of behavioral parameters like social behavior, spatial learning and memory and anxiety like behaviors. Additionally, the levels of various dopaminergic markers, including the long and short form of the D2 receptor, and total and phosphorylated dopamine and cyclic adenosine 3′,5′-monophosphate regulated phosphoprotein-32, and proteins involved in intracellular trafficking were assessed in several key brain regions in young adult mice.MethodsMouse model of chronic social defeat was established by resident-intruder paradigm, and to evaluate the effect of chronic social defeat, mice were subjected to behavioral tests like spontaneous locomotor activity, elevated plus maze (EPM), social interaction and Morris water maze tests.ResultsMice were divided into susceptible and unsusceptible groups after 10 days of social defeat stress. The susceptible group exhibited greater decreases in time spent in the open and closed arms compared to the control group on the EPM. In the social interaction test, the susceptible group showed greater increases in submissive and neutral behaviors and greater decreases in social behaviors relative to baseline compared to the control group. Furthermore, increased expression of D2L, D2S, Rab4, and G protein-coupled receptor associated sorting protein-1 was observed in the amygdala of the susceptible group compared to the control group.ConclusionThese findings suggest that social defeat stress induce anxiety-like and altered social interacting behaviors, and changes in dopaminergic markers and intracellular trafficking-related proteins.Electronic supplementary materialThe online version of this article (10.1186/s12993-018-0148-5) contains supplementary material, which is available to authorized users.

Obese mice exposed to psychosocial stress display cardiac and hippocampal dysfunction associated with local brain-derived neurotrophic factor depletion

“…Both obesity and PS can separately generate anxiety [58,59]. Therefore, using the elevated plus maze (EPM) test specifically designed for this purpose [60], we next determined how effective obesity and PS are in triggering anxiety, when administered alone or in combination.…”

Behavioral Traits Associated With Resilience to the Effects of Repeated Social Defeat on Cocaine-Induced Conditioned Place Preference in Mice

“…This reduction of the ISI in defeated mice has been associated with the social avoidance that characterizes affective disorders (Golden et al, 2011), and has been repeatedly observed after RSD or social instability (Krishnan et al, 2007;Golden et al, 2011;Henriques-Alves and Queiroz, 2016;Browne et al, 2018;Dong et al, 2018;Hodges et al, 2018). Furthermore, the ISI is the most used measure to distinguish between mice that are resilient or vulnerable to the effects of different models of social defeat (Krishnan et al, 2007;Chaudhury et al, 2013;Donahue et al, 2014;Friedman et al, 2014;Hodes et al, 2014;Isingrini et al, 2016;Sun et al, 2016;Nelson et al, 2018;Prabhu et al, 2018;Gururajan et al, 2019). In this line, we have also observed a subgroup of resilient mice (with similar ISI to that of control mice) and another subgroup of vulnerable mice that displayed social avoidance.…”

Effects of Stathmin 1 Gene Knockout on Behaviors and Dopaminergic Markers in Mice Exposed to Social Defeat Stress

“…The following tests were performed before and after SDS: novel object recognition test (NORT), open field test (OFT) and social interaction test (SIT). The detailed procedures were described in our previous studies [24,25,26].…”

“…Two isoforms of the D2R, D2L and D2S have been analyzed previously and a few modifications were observed [33,34]. A detailed description of this analysis was reported in our previous study [26]. Glutaraldehyde-treated membranes were incubated in 5% skimmed milk overnight at 4 °C with rabbit polyclonal antibodies against D2L (1:2000) and D2S (1:5000) (AbClon, Inc., Seoul, Korea).…”