Influence of Oxytocin on the Startle Reflex and on Its Modulation

Sponsor

University of Zurich (Other)

Overall Status

Unknown status

CT.gov ID

NCT01066299

Collaborator

University of Basel (Other), University of Freiburg (Other)

Enrollment

Location

Arms

Duration (Months)

1.6

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

Oxytocin (OXT) is currently regarded as a crucial neuropeptide in the mediation of various human social behaviors, e.g. social affiliation, social recognition, and the modulation of anxiety, mood, and aggression. An impairment of social behavior, emotional regulation as well as increased stress reactions are characteristic of several psychiatric conditions, including schizophrenia, social anxiety and PTSD, in which there is also some evidence for OXT dysfunction. The startle reflex is a basic defensive reaction that can be modulated by emotional stimuli. The investigation of the startle reflex and of its modulation is a well-validated method to test stress reactions and emotional regulation. These processes are impaired in the same psychiatric diseases, in which OXT dysfunction was evidenced. Although previous animal studies showed that the dysfunction of brain OXT systems might be implicated in startle reflex and in its modulation, no study has been performed yet in human that investigated the influence of OXT administration on the startle response and on its affective modulation. A first aim of this study is to investigate the influence of OXT on stress reactivity and emotional modulation in healthy humans. A second aim is to develop a method for the investigation of anxiety disorders. Fifty male healthy participants will be tested using a randomized double-blind placebo-controlled cross-over design in two occasions; once with administration of 24 IU OXT, and once with placebo using nasal sprays while performing a computer-based experiment, in which emotional pictures and auditory startle probes are presented. We will measure the subject's subjective ratings of the pictures as well as the facial EMG activation, heart rate and electrodermal activation throughout the study. This project offers a unique opportunity to study the relationship between the OXT system and basic motivational and emotional behaviors. The investigation of these mechanisms is in turn greatly worthwhile, not only for understanding of the neurochemical and physiological processes involved in emotional regulation, but also for the comprehension of the neuroendocrine and neurophysiological mechanismsunderlying anxiety disorders. In the long term, it could open the possibilities of OXT as a psychobiological therapeutics of psychiatric disorders.

Condition or Disease	Intervention/Treatment	Phase
Psychiatric Disorders	Drug: Syntocinon® Drug: inactive nasal spray	N/A

Study Design

Study Type:

Interventional

Anticipated Enrollment :

50 participants

Allocation:

Randomized

Intervention Model:

Crossover Assignment

Masking:

Double (Participant, Investigator)

Primary Purpose:

Basic Science

Official Title:

A Randomized, Double-blind, Placebo-controlled Single-center Study on the Influence of Oxytocin on the Startle Reflex and on Its Modulation in Healthy Male Subjects

Study Start Date :

May 1, 2010

Anticipated Primary Completion Date :

Sep 1, 2012

Anticipated Study Completion Date :

Dec 1, 2012

Arms and Interventions

Arm	Intervention/Treatment
Experimental: oxitocin nasal spray oxytocin nasal spray	Drug: Syntocinon® single dose of OXT (24 IU)
Placebo Comparator: placebo inactive nasal spray	Drug: inactive nasal spray single dose (24 IU)

Arm

Intervention/Treatment

Experimental: oxitocin nasal spray

oxytocin nasal spray

Drug: Syntocinon®

single dose of OXT (24 IU)

Placebo Comparator: placebo

inactive nasal spray

Drug: inactive nasal spray

single dose (24 IU)

Outcome Measures

Primary Outcome Measures

Eye blink response to the tones measured as the peak activity of the left musculus orbicularis oculi that will be compared between the active drug and the placebo conditions. [1 year]

Secondary Outcome Measures

Anxiety ratings assessed with the State-Trait-Inventory that will used as a covariate in the ANOVAs. [1 year]

Eligibility Criteria

Criteria

Ages Eligible for Study:

18 Years to 65 Years

Sexes Eligible for Study:

Male

Accepts Healthy Volunteers:

Yes

Inclusion Criteria:

gender: male
age > 18 years
good command of German
non-smoker

Exclusion Criteria:

impaired cognitive abilities
past or current psychiatric or neurological disorder
other relevant somatic disease (including liver, kidney or heart diseases - -- allergy to preserving agents (Paraben contained in nasal spray)
other medication including hormonal and herbal medication
participation in other clinical studies within one month
impaired hearing