Healthy Volunteers
Conditions
Brief summary
The purpose of this study is to determine whether oxytocin modulates the processing of stress-associated chemosignals and which substrates are involved.
Detailed description
Social transmission of stress and fear is not restricted to visual or auditory cues, but extends to the olfactory domain, a phylogenetically more ancient sense. Exposure to axillary sweat from healthy volunteers undergoing an emotional stressor task evokes a strong vicarious stress response on the behavioral and neural level.Particularly, anxious individuals have been shown to exhibit a heightened sensitivity to social chemosensory stress cues (axillary sweat). The neuropeptide oxytocin (OXT) exerts anxiolytic and anti-stress effects in visual and auditory modalities, however, it still elusive whether OXT also modulates the processing of stress-associated chemosignals. Axillary sweat were obtained from an unrelated sample of 30 healthy men undergoing the Trier Social Stress Test and ergometer training as control.Subsequently, subjects completed a forced-choice emotional face recognition task composed of stimuli with varying intensities (neutral to fearful), while they were exposed to both sweat stimuli and a non-social control odor (raspberry) after OXT or placebo administration, respectively. The investigators expect that OXT selectively diminishes chemosensory-induced behavioral biases and neural responses to stress-related odors.
Interventions
DRUGPlacebo
Placebo nasal spray, 5 puffs balanced across nostrils, at an inter-puff interval of 30 seconds
DRUGOxytocin
40 IU; 5 puffs balanced across nostrils, at an inter-puff interval of 30 seconds
Sponsors
University Hospital, Bonn
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
DOUBLE (Subject, Investigator)
Eligibility
Sex/Gender
ALL
Age
18 Years to 40 Years
Healthy volunteers
Yes
Inclusion criteria
* Healthy volunteers * Right-handed
Exclusion criteria
* Current or past psychiatric disease * Current or past physical illness * Psychoactive medication * Tobacco smokers * MRI contraindications (e.g. metal in body, claustrophobia) * Anosmia * Medication known to interfere with olfactory processing
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Response time for facial stimuli ratings. | 30 min after nasal spray administration | — |
| Blood-oxygen-level dependent signal in response to chemosensory cues. | 30 minutes after nasal spray administration | The modulatory effect of oxytocin on neural correlates Using functional magnetic resonance imaging, signal changes in the amygdala, hippocampus and the anterior cingulate cortex in response to olfactory cues of stress and sport (axillary sweat obtained from an unrelated sample of 30 healthy men undergoing the Trier Social Stress Test and ergometer training as control). |
| Forced-choice ratings of morphed emotional faces with varying intensities (neutral to fearful). | 30 min after nasal spray administration | After each trial, subjects were asked to use a button response grip to indicate whether they perceived the depicted face as neutral or fearful. |
Secondary
| Measure | Time frame |
|---|---|
| Questionnaire measurement of mood (PANAS). | 15 minutes before the nasal spray administration and (on average) 10 minutes after the fMRI experiment |
| Saliva oxytocin concentrations | immediately before the nasal spray administration and (on average) 10 minutes after the fMRI experiment |
| Questionnaire measurement of anxiety (STAI). | 15 minutes after nasal spray administration and (on average) 10 minutes after the fMRI experiment |
Outcome results
None listed