Oxytocin facilitates the sensation of social stress

Abstract

Essentially all social species experience social stress which can be a catalyst for detriments in mental and physical health. The neuropeptide oxytocin (OXT) has been shown to produce anxiolytic and antistress effects, thereby qualifying the OXT system as a promising drug target in the treatment of stress-related disorders. However, recently it has been shown that OXT can have anxiogenic effects as well. In the present study, we used functional magnetic resonance imaging to scan the brains of 60 healthy men while they were exposed to social stress after they received either intranasal OXT (24 IU) or placebo treatment. Although OXT administration did not alter salivary cortisol levels as a surrogate marker of stress axis activity, our participants initially reported an increment in perceived social stress. This behavioral effect was paralleled on the neural level by increased activity in the precuneus and cingulate cortex. Taken together, our results support the hypothesis that OXT can induce a self-referential processing bias which facilitates the sensation of social stress in the absence of altered endocrine responses.

Oxytocin Facilitates Pavlovian Fear Learning in Males

“…In the present study, OXT enhanced pMCC responses to social stimuli during fear conditioning, which is consistent with findings in mice suggesting that OXT specifically facilitates social fear conditioning (Zoicas et al, 2014). Taken together with previous research (Eckstein et al, 2014a;Striepens et al, 2012), this study presents a model of OXT as an enhancer of adaptation in social contexts. This heightened ability to adapt could, however, simultaneously be the groundwork for debilitating hypersensitivity to cues if extinction is not successful.…”

“…Indeed, we observed strengthened activity in the sACC for all fear-associated stimuli (CS+) and in the pMCC for the social fear-associated stimulus (face CS+). This specific profile suggests that OXT facilitates Pavlovian fear conditioning by potentiating neural responses to fearassociated stimuli in regions other than the amygdala, highlighting their importance in the acquisition of fear (Eckstein et al, 2014a;Striepens et al, 2012). Furthermore, in accordance with previous findings (Rash et al, 2014), OXT attenuated both neural and psychophysiological responses to the aversive electric shock.…”

“…Based on previous studies investigating the neural effects of OXT (Eckstein et al, 2014a;Scheele et al, 2014a), we defined regions of interest (ROIs) for the amygdala (Hurlemann et al, 2008) and subdivisions of the cingulate cortex (ie, the anterior cingulate cortex (ACC) and the middle cingulate cortex (MCC)) (Vogt, 2005) by applying atlas-based structural ROI masks. A significance threshold of Po0.05, corrected for multiple comparisons (family-wise error (FWE)), was used.…”

“…We expected this to be evident in psychophysiology as well as in fear-related neural networks (Sehlmeyer et al, 2009). These networks include the amygdala as well as middle and anterior parts of the cingulate cortex, which are involved in negative affect (Vogt, 2005) and whose activations have been found to be susceptible to OXT IN (Eckstein et al, 2014a, b;Preckel et al, 2014;Scheele et al, 2014a, b).…”

“…Indeed, the prevailing pathomechanistic models of anxiety disorders have emphasized a key role of Pavlovian fear conditioning in the acquisition of avoidance behavior (Lissek et al, 2008;Rauch et al, 2006). This finding of increased fear extinction, however, seems to contradict further research showing that OXT IN facilitates bodily reactions to and episodic memory for aversive events , increases the perception of social stress in the absence of support (Eckstein et al, 2014a), and promotes defensive aggression towards competing outgroups (De Dreu et al, 2010). We therefore sought to answer the question whether OXT's influence is dependent on the timing of administration.…”