Oxytocin and Reward Processing in Women
Trial statusRecruiting
Trial phaseNot applicable
Trial typeInterventional
Biological sexFemale
Age18-40
SponsorInternational Research Training Group 2804
About this trial
Oxytocin is a hypothalamic neuropeptide that is best known for its peripheral physiological effects in the female organism i.e., uterine contractions during birth. The neuropeptide furthermore affects reward processing and metabolic functions such as eating behavior and body weight. Oxytocin receptors are present in brain regions associated with the processing of rewards, e.g., ventral tegmental area (VTA), nucleus accumbens (NAcc) and nucleus stria terminalis.
Previous studies indicate that oxytocin interacts with sex hormones such as estradiol in a sex-specific manner. Despite known sex differences in oxytocin function, most studies i.e., on the metabolic effects of oxytocin in humans have so far focused on young, healthy men.
Intranasal oxytocin administration has emerged as a method to experimentally investigate central nervous effects of oxytocin in the absence of relevant side effects.
In the proposed study the investigators aim to systematically investigate the acute effect of intranasal oxytocin on reward processing in relation to circulating and synthetic sex hormones in healthy, naturally cycling women and in women taking hormonal oral contraceptive pills. The investigators will administer 24 international units (IU) of intranasal oxytocin vs. placebo and investigate neural correlates in a 3T MRI scanner including functional imaging during a reward processing task, changes in brain anatomy and connectivity. Additionally, metabolic functions, eating behavior and changes in mood and wellbeing will be assessed and blood will be drawn to assess parameters of hormonal and metabolic status.
Eligibility criteria
This trial accepts healthy volunteersQualifiers
Body-mass index (BMI): 18-28 kg/m2
Sex: female (since birth)
Normal or corrected vision
Natural menstrual cycle (NC) or intake of hormonal oral contraceptives (OC)
Disqualifiers
No German language fluency (due to German language test content)
Smoking
Medication taken within the last 6 weeks (except for OCs in the respective group)
Current neurological or psychiatric disease (anamnestic survey)
Trial design
Design model
Crossover
Treatments tested in this trial
Intranasal oxytocin administration
Drug24 international units (IU) of Syntocinon, nasal spray solution; 1 ml nasal spray contains 40 I.U. oxytocin (equivalent to 67 mcg). One spray hub (0.1 ml) contains 4 I.U. oxytocin (equivalent to 6.7 mcg).
Intranasal placebo administration
DrugNasal spray solution; Placebo will be administered as the placebo controlled condition.
Treatment groups
100 Participants
are divided into 4 treatment groupsGroup A: NC follicularExperimental treatment 2 interventions
Group B: NC lutealExperimental treatment 2 interventions
Group C: OC combinedExperimental treatment 2 interventions
Group D: OC progestogen-onlyExperimental treatment 2 interventions
Trial outcomes
Primary outcomes
1
Oxytocin and sex hormone level induced changes in reward-related brain responses in the reward circuitry during effort-based decision making.
Comparing brain activity (BOLD signals) in the reward circuitry (ROIs: nucleus accumbens, putamen, caudate, ventral tegmental area, amygdala, ventromedial prefrontal cortex, orbitofrontal cortex, anterior cingulate cortex, insula) and cognitive control areas (ROIs: dorsolateral and ventromedial prefrontal cortex, anterior cingulate cortex, supplementary motor area) of female participants in luteal menstrual cycle phase, follicular menstrual cycle phase, with combined OC intake and progestogen-only OC intake during a reward task with oxytocin vs placebo.
Time frame
During neuroimaging (60 minutes) oxytocin compared to placebo condition.2
Oxytocin induced changes in reward related behavior.
Force exerted on grip force controller to obtain rewards and changes in behavioral parameters measured during the Effort Allocation Task after oxytocin vs. placebo administration.
Time frame
During neuroimaging (60 minutes) oxytocin compared to placebo condition.3
Oxytocin induced changes in eating behaviour.
Number of consumed calories (kcal) in a snack test and subjective satiety in oxytocin vs. placebo condition.
Time frame
During the experimental session (approximately 4.5 hours).Secondary outcomes
1
Oxytocin induced changes in functional connectivity.
Functional connectivity of regions of the mesocorticolimbic circuitry (ROIs: nucleus accumbens, putamen, caudata, ventral tegmental area, amygdala, ventral medial prefrontal cortex, orbitofrontal cortex, anterior cingulate cortex) and limbic circuity (ROIs: hypothalamus, hippocampus) after oxytocin vs. placebo administration.
Time frame
During neuroimaging (60 minutes) oxytocin compared to placebo condition.2
Oxytocin induced changes in stress-axis reactivity.
Cortisol concentrations assessed by blood samples after oxytocin vs. placebo administration.
Time frame
During the experimental session (approximately 4.5 hours).3
Sex hormone induced changes in energy expenditure.
Changes in resting energy expenditure, measured by indirect calorimetry.
Time frame
Measured in each experimental session, approximately 4 weeks apart; between-subject outcomeSponsors and contacts
Click on the lead sponsor to view all of their trials.
International Research Training Group 2804
Lead sponsor
University Hospital Tuebingen
Collaborator
German Research Foundation
Collaborator
Uppsala University
Collaborator
Source ClinicalTrials.gov