With this research we would like to assess the effects of cortisol on the brain, and determine whether these effects are region- and time-specific. Our main interest is focused on the effects of cortisol on the regions involved in memory formation…
ID
Source
Brief title
Condition
- Other condition
Synonym
Health condition
geen aandoening
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
The main variable of interest is the brain activity measured during the
computer tasks, in combination with the cortisol levels assessed from the
participant*s saliva. To determine this level participants will be asked
several times during the experiment to chew on a cotton cloth in order to
obtain saliva. By comparing the data between groups we will be able to
elucidate the effects of cortisol on the brain and to determine the time- and
region-dependency.
Secondary outcome
Besides brain activity we will measure several physiological and psychological
measures during fMRI scanning; heart beat, blood pressure, skin conductance,
pupil size, eye movement, reaction times, and the mood of the participant.
These variables, in combination with personality traits assessed by several
questionnaires, can be entered in the analysis of the cortisol effects as well.
Background summary
Stressful events have a privileged position in memory. The effects of so-called
stress hormones on the brain are held responsible for this. Cortisol is such a
stress hormone that is known to bind to specific receptors localized in the
brain, but which effect on brain activity and function are still rather
unknown. Animal studies have shown that cortisol has potentially contradicting
rapid direct, and slow genomic effects on the brain.
Study objective
With this research we would like to assess the effects of cortisol on the
brain, and determine whether these effects are region- and time-specific. Our
main interest is focused on the effects of cortisol on the regions involved in
memory formation and related higher cognitive functions, as working memory,
attention and emotional processing; the medial temporal lobe (MTL) and the
prefrontal cortex (PFC).
Study design
All participants will be invited to the lab for two subsequent afternoons. The
first afternoon they will receive two tablets (doubleblind) at different time
points, of which maximally one contains 10 mg hydrocortisone and the other
placebo (see *Intervention*). By elevating the level of cortisol either 240
minutes or 30 minutes prior to a functional MRI session, we will be able to
both assess the slow genomic and rapid direct effects of cortisol on the brain.
During the functional MRI session participants are asked to conduct several
computer tasks, which activate the regions of interest; the MTL and PFC. These
tasks assess long term memory, working memory, emotional processing, attention,
and rest. The second afternoon participants are asked to return to the center,
and have to conduct a short memory test for some of the information studied in
the scanner.
Intervention
Participants will by randomly assigned to one of the three groups. During the
first afternoon, each group will receive two tablets, at different time points
prior to the scanning session:
- group 1: 240 min prior to scanning 10 mg hydrocortisone
30 min prior to scanning placebo
- group 2: 240 min prior to scanning placebo
30 min prior to scanning 10 mg hydrocortisone
- group 3: 240 min prior to scanning placebo
30 min prior to scanning placebo
Study burden and risks
Both the burden and risk of participation are not considered to be high. The
research requires a total time-investment of 7 hours, divided over two
subsequent afternoons. All procedures followed are without any danger and we do
not expect any side effects from the proposed administration of such a low dose
of hydrocortisone that is administered only once.
P.O. Box 9101
6500 HB Nijmegen
Nederland
P.O. Box 9101
6500 HB Nijmegen
Nederland
Listed location countries
Age
Inclusion criteria
• Healthy male volunteers between 18 and 45 years of age
• Predominant right-handedness
• Body mass index between 18.5 and 30
Exclusion criteria
• Abnormal (uncorrected) vision
• Average use of more than 3 alcoholic beverages daily and a self-reported inability or unease to cease drinking alcohol for 24 hours prior to testing
• Use of psychotropic medication
• Average use or recreational drugs weekly or more
• Habitual smoking, i.e. more than a package of cigarettes per week and a self-reported inability or unease to cease smoking for 24 hours prior to testing
• Use of recreational drugs over a period of 72 hours prior to each test session, and use of alcohol within the last 24 hours before each measurement
• Regular use of corticosteroids
• Metal objects in or around the body (braces, pacemaker, metal fragments, hearing devices)
• History of psychiatric treatment or current psychiatric treatment
• History of neurological treatment or current neurological treatment
• History of endocrine treatment or current endocrine treatment
• History of autonomic failure (e.g., vasovagal reflex syncope)
• Current parodontitis
• Claustrophobia
• Irregular sleep/wake rhythm (e.g., regular nightshifts or cross timeline travel)
• Active peptic or duodenal ulcers
• Active inflammatory disease
Design
Recruitment
Medical products/devices used
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In other registers
| Register | ID |
|---|---|
| CCMO | NL26345.091.08 |