Oxytocin and Reward Processing in Women

Summary

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.

Conditions

• Menstrual Cycle
• Hormonal Contraception

Interventions

DRUG

Intranasal oxytocin administration

24 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).

DRUG

Intranasal placebo administration

Nasal spray solution; Placebo will be administered as the placebo controlled condition.

Sponsors & Collaborators

• University Hospital Tuebingen

  collaborator OTHER

• German Research Foundation

  collaborator OTHER

• Uppsala University

  collaborator OTHER

• International Research Training Group 2804

  lead OTHER

Principal Investigators

• Manfred Hallschmid, Professor · Institute of Medical Psychology and Behavioural Neurobiology

Study Design

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

TRIPLE

Model

CROSSOVER

Eligibility

Min Age

18 Years

Max Age

40 Years

Sex

FEMALE

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2024-02-16

Primary Completion

2026-12-31

Completion

2026-12-31

Countries

• Germany

Study Locations