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Investigating Stress-Induced Dopamine Release: a fMRI-PET Study

Not Applicable
Completed
Conditions
Stress Response
Interventions
Device: tDCS Sham
Device: tDCS actif
Registration Number
NCT05825677
Lead Sponsor
Hôpital le Vinatier
Brief Summary

The stress response is mediated by the activation of the hypothalamo-pituitary-adrenal axis and the sympathetic nervous system, leading to glucocorticoid and catecholamines release respectively. This stress response is regulated by feedback loops, involving cortical and subcortical structures.

Non-invasive brain stimulation applied over the dorsolateral prefrontal cortex modulates the subcortical dopaminergic transmission at rest and can reduce the hormonal and cognitive alterations induced by stress. This study aims to investigate the Non-invasive brain stimulation -induced modulation of dopamine transmission in an acute stress situation.

Detailed Description

Objective: to investigate the influence of Dorsolateral Prefrontal Cortex stimulation during acute stress on the subcortical dopamine transmission in healthy subjects.

Method: 30 healthy subjects will be enrolled and randomized into 2 parallel groups. 15 participants will receive active Transcranial direct current stimulation , the other 15 participants will receive sham Transcranial direct current stimulation.

Transcranial direct current stimulation procedure: active Transcranial direct current stimulation corresponds to 30min of stimulation at 1mA intensity . The sham stimulation corresponds to 30s of real stimulation.

Stress paradigm: In order to induce moderate stress in humans in laboratory condition, the investigators will use the Maastricht Acute Stress test . This test is a combination between physical, hand immersion in cold water and cognitive calculation stress. The test will start 5 minutes after the beginning of stimulation session.

Stress measures: the stress response will be evaluated at the following levels:

* Neurochemical level: dopamine transmission measured with positron emission tomography

* Functional brain connectivity: resting-state networks measured with functional magnetic resonance imaging

* Hormonal level: adrenocorticotropic hormone and cortisol levels measured with blood samples

* Cognitive level: decision-making and memory assessed with delay-discounting task and reality-monitoring task, respectively

* Molecular level: expression of genes involved in the glucocorticoid receptor signaling pathway measured through blood samples Exploratory measure: Brain-Derived Neurotrophic Factor and cytoplasmic catechol-O-methyltransferase polymorphisms of participants involved in differential Transcranial direct current stimulation response will be assessed.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
34
Inclusion Criteria
    • Men and women aged between 18- and 30-year-old
  • Non-smoker
  • Non-psychotropic user
Exclusion Criteria
    • Have a psychiatric or somatic disorder
  • Have a first-degree family history of a psychiatric disorder
  • Pregnant or nursing women
  • Be on medication, with the exception of oral contraceptives
  • Contraindications to tDCS or MRI examination
  • Participants with pacemaker or cardiac or cerebral implant

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
Sham tDCStDCS ShamSham brain stimulation Direct current stimulation of DLPFC for 30sec with an intensity of 1mA
Active tDCStDCS actifActive brain stimulation Direct current stimulation of DLPFC for 30min with an intensity of 1mA
Primary Outcome Measures
NameTimeMethod
Dopamine transmission measured with positron emission tomographyOne year

Subcortical dopaminergic transmission will be analyzed, using \[11C\]raclopride PET activity (D2 receptor antagonist)

Secondary Outcome Measures
NameTimeMethod
Functional brain connectivityOne year

Resting-state functional connectivity

Hormonal stress reactivityOne year

Cortisol level will be measured

Cognitive stress reactivityOne year

Decision-making capacities will be measured using a computerized version of the DDT in which participants have to choose between 2 rewards. Memory capacities will be measured using a computerized task evaluating reality-memory.

Expression of genes involved in the glucocorticoid receptor signaling pathway measured through blood samplesOne year

Expression rates of genes involved in the glucocorticoid receptor signaling pathway

Assessment of brain-derived neurotrophic factor before and after transcranial direct current stimulation.One year

Exploratory measure: brain-derived neurotrophic factor polymorphisms of participants, involved in differential Transcranial direct current stimulation response, will be assess.

Assessment of Cytoplasmic catechol-O-methyltransferase polymorphisms before and after transcranial direct current stimulation.One year

Exploratory measure: Cytoplasmic catechol-O-methyltransferase polymorphisms of participants, involved in differential Transcranial direct current stimulation response, will be assess.

Trial Locations

Locations (1)

Ch Le Vinatier

🇫🇷

Lyon, Rhone Alpes, France

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