Serotonin 4 receptor brain binding and oxytocin-promoted affective and social cognition in healthy women – A randomized controlled trial

Background: Oxytocin is a neuropeptide known for its prosocial properties and role in social bonding, and intervention with intranasal oxytocin is posited to modulate affective and social cognition (i.e., hot cognition). Serotonin (5-HT) neurotransmission is also involved in emotional and social behaviors and appear to work in concert with oxytocin. However, this interaction so far remains elusive in humans. Therefore, we here investigate the relation between brain 5-HT 4 receptor (5-HT4R) levels and oxytocin-modulated hot cognition. Methods: Using a double blind, placebo-controlled, randomized crossover design, 35 healthy women received a dose of 24 IU intranasal oxytocin or placebo one month apart. The women were naturally cycling and to control for hormonal fluctuations across the menstrual cycle, intervention days were placed during the early follicular phase. Following intervention cognitive domains including affective memory, affective bias in emotion processing, moral emotions and social information preference were assessed. In a subgroup (n = 25), Positron Emission Tomography (PET) was used to image 5-HT4R brain binding at baseline with the [11C]SB207145 radiotracer. Results: No effect of oxytocin intervention relative to placebo was observed for any of the cognitive outcomes. Likewise, regional brain 5-HT4R binding at baseline was not associated with cognitive responses to oxytocin intervention. Conclusion: Our data suggest that intervention with intranasal oxytocin does not have an overall effect on hot cognition in healthy women and further that 5-HT4R brain architecture does not mediate cognitive effects of oxytocin in the healthy state

Trait aggression is associated with five-factor personality traits in males

BACKGROUND: Although aggression is conceptualized as a dimensional construct with violent behavior representing the extreme end of a spectrum, studies on the involvement of personality traits in human aggression have typically only included data representing a restricted spectrum of aggressive behaviors. METHODS: In the current study, we therefore examine whether trait aggression is associated with five‐factor model personality traits in an enriched sample of 259 men with a broad continuum of trait aggression, ranging from very low to very high including 39 incarcerated aggressive violent offenders. All participants completed the NEO Personality Inventory‐Revised (NEO PI‐R) and the Buss–Perry Aggression Questionnaire (BPAQ). The association between each of the five NEO PI‐R personality traits and trait aggression (BPAQ) was investigated using five linear regression models, covarying for group status, age and educational level. RESULTS: Higher BPAQ scores were positively associated with Neuroticism and negatively associated with Agreeableness and Conscientiousness. CONCLUSION: Our results indicate that those high in Neuroticism and low in Agreeableness and Conscientiousness are at higher risk of exhibiting aggressive behavior, underlining the relevance of these higher order personality traits in understanding aggressive behavior. We argue that studying individual personality differences should be offered a greater attention within violent and criminal behaviors