Effects of Ketamine on Eye Movements, Perception and Brain Function

NCT ID: NCT02701933

Last Updated: 2016-03-08

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 24 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2014-04-30
• Study Completion Date: 2014-12-31

Brief Summary

In this study, the investigators examine the effects of low-dose ketamine on different oculomotor, perceptual and cognitive functions. They also examine effects on concurrent brain activity using blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI). A sample of N=25 healthy, male participants is required to complete the study. The design is within-subjects, placebo-controlled, double-blind and cross-over. A targeted ketamine level in plasma of 100ng/ml is applied. It is hypothesised that ketamine, compared to placebo, will lead to changes in task performance and brain activity similar to those observed in patients with schizophrenia.

Detailed Description

The uncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist ketamine has been proposed as a model system of the symptoms of schizophrenia. To complement this model system and to allow neurobiological as well as translational studies, biomarkers are often applied to people under the influence of ketamine. Here, we apply oculomotor, perceptual and cognitive biomarkers to healthy human volunteers whilst they undergo BOLD fMRI at 3 Tesla field strength. We use a counter-balanced, placebo-controlled, double-blind, within-subjects design. A sample of 25 healthy participants is required. Participants will receive intravenous (IV) racemic ketamine (with a 100ng/ml target plasma concentration) on one of two assessment days and they will receive placebo (intravenous saline) on the other assessment day. BOLD fMRI will be carried out on a Siemens Trio scanner at the Life&Brain Centre, Bonn. In addition to brain functional and cognitive, perceptual and oculomotor responses, we will also measure self-ratings of psychosis-like experiences. These will be obtained using the Psychotomimetic States Inventory (PSI; Mason et al 2008).

Conditions

Functional Neuroimaging

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: TRIPLE

Study Groups

Ketamine-Saline

Each participant receives both ketamine and placebo (saline) in randomised order in a repeated-measures design. In this arm, ketamine is administered on the first assessment and placebo (saline) is administered on the second assessment.

Group Type: OTHER

Ketamine

Intervention Type: DRUG

Racemic ketamine, intravenous, at a concentration of 10mg ketamine per 50ml infusion

Saline

Intervention Type: DRUG

Saline, intravenous infusion

Saline-Ketamine

Each participant receives both ketamine and placebo (saline) in randomised order in a repeated-measures design. In this arm, placebo (saline) is administered on the first assessment and ketamine is administered on the second assessment.

Group Type: OTHER

Ketamine

Intervention Type: DRUG

Racemic ketamine, intravenous, at a concentration of 10mg ketamine per 50ml infusion

Saline

Intervention Type: DRUG

Saline, intravenous infusion

Interventions

Ketamine

Racemic ketamine, intravenous, at a concentration of 10mg ketamine per 50ml infusion

Intervention Type: DRUG

Saline

Saline, intravenous infusion

Intervention Type: DRUG

Other Intervention Names

Ketamin Ratiopharm; Kochsalzloesung

Eligibility Criteria

Inclusion Criteria

• MRI-suitability
• suitability for video-based combined pupil and corneal reflection (VCPCR) eye-tracking
• good command of German language
• willingness to take part

Exclusion Criteria

• any current or history of axis I disorder diagnosis as assessed by the Mini-International Neuropsychiatric Interview (M.I.N.I.)
• any neurological conditions and heart conditions
• use of any prescription or non-prescription medication up to one week before participation
• personal history of head-injuries, loss of consciousness, eye surgery or impairment of vision (other than corrective lenses)
• any other relevant medical conditions such as high blood pressure
• positive urine drug test (Drug-Screen Multi "5T", nal von minden GmbH)
• history of drug use or current drug use
• under- or overweight (below 18.5 and above 24.9 body mass index (BMI) values)
• any diagnosis of psychotic disorders among first-degree relatives

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 45 Years
• Eligible Sex: MALE
• Accepts Healthy Volunteers: Yes

Sponsors

University of Bonn

OTHER

Sponsor Role: lead

Responsible Party

Ulrich Ettinger

Professor of Psychology

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Ulrich Ettinger, PhD

Role: PRINCIPAL_INVESTIGATOR

Department of Psychology, University of Bonn

Locations

University of Bonn

Bonn, North Rhine-Westphalia, Germany

Countries

Germany

Other Identifiers

#14-03-20

Identifier Type: -

Identifier Source: org_study_id