Dose-dependent Effects of Oxytocin on the Amygdala and Reward System

Study Overview
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Brief Summary
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The purpose of this study is to determine whether effects of intranasal oxytocin on amygdala and reward system responses vary as a function of treatment dose in women in comparison to men.

Detailed Description
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The objective of the present study is to determine whether intranasal oxytocin (IN-OXT) effects on blood oxygenation level-dependent functional magnetic resonance imaging (BOLD fMRI) in the amygdala and striatal regions (putamen, nucleus accumbens, caudate, pallidum) vary as a function of dose. In particular, the investigators plan to compare effects of three different IN-OXT doses (6, 12, and 24 international units, IU) on established neural and behavioural correlates of emotion processing in women. Results will be discussed in comparison to a previous study of OXT kinetics in men.

Official Title
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Dose-dependent Effects of Oxytocin on the Amygdala and Reward System Vary Between Women and Men

Conditions
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Healthy

Intervention / Treatment
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* Drug: Oxytocin nasal spray
* Drug: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy female volunteers Right-handed Non-smoker Exclusion Criteria: Current psychiatric or physical illness Hormonal contraception Psychoactive medication MRI contraindication (e.g. metal in body, claustrophobia) Pregnancy

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 40 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Oxytocin & Placebo, 6 IU<br>Intranasal administration, 6 IU oxytocin nasal spray or placebo. Imaging starting 45 min after nasal spray administration. | Drug: Oxytocin nasal spray<br>* Intranasal administration, 6, 12, or 24 international units (IU) oxytocin.<br>Drug: Placebo<br>* The placebo nasal sprays contain identical ingredients except for the peptide itself.<br>|
| Active Comparator: Oxytocin & Placebo, 12 IU<br>Intranasal administration,12 IU oxytocin nasal spray or placebo. Imaging starting 45 min after nasal spray administration. | Drug: Oxytocin nasal spray<br>* Intranasal administration, 6, 12, or 24 international units (IU) oxytocin.<br>Drug: Placebo<br>* The placebo nasal sprays contain identical ingredients except for the peptide itself.<br>|
| Active Comparator: Oxytocin & Placebo, 24 IU<br>Intranasal administration, 24 IU oxytocin nasal spray or placebo. Imaging starting 45 min after nasal spray administration. | Drug: Oxytocin nasal spray<br>* Intranasal administration, 6, 12, or 24 international units (IU) oxytocin.<br>Drug: Placebo<br>* The placebo nasal sprays contain identical ingredients except for the peptide itself.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Neural substrates of emotion processing, measured via blood-oxygen-level dependent signal in the amygdala | Functional magnetic resonance imaging (fMRI) will be performed to measure blood-oxygen-level dependent signal in response to emotional face stimuli. The investigators specifically plan to investigate amygdala responses to emotional faces, because previous studies found sex-specific effects of oxytocin on amygdala activation. | 45 min after nasal spray administration | 
| Neural substrates of emotion processing, measured via blood-oxygen-level dependent signal in striatal regions (putamen, nucleus accumbens, caudate, pallidum) | Functional magnetic resonance imaging (fMRI) will be performed to measure blood-oxygen-level dependent signal in response to emotional face stimuli. The investigators specifically plan to investigate striatal responses to emotional faces to explore sex-specific effects of OXT on reward-related brain activation. | 45 min after nasal spray administration | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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amygdala, reward, oxytocin, dose, emotion processing, sex differences