The Role of the Renin-angiotensin System in Reward Reinforcement Learning
Trial Snapshot
- Phase
- Not Applicable
- Sponsor
- Enrollment
- 60
- Locations
- 1
- Primary Endpoint
- BOLD-level activity as assessed by fMRI during the learning phase
Study Overview
Brief Summary
This study aims to investigate whether a single dose of losartan (50 mg) can affect learning from positive and negative outcomes and its related neural mechanisms.
Detailed Description
Emerging evidence suggests that the renin-angiotensin system can impact dopamine (DA) transmission and its modulatory role in reward processing. For instance, recent animal models have found that the angiotensin antagonist losartan reduces rewarding effects of methamphetamine and nicotine by modulating DA release in the striatum.The present study thus will investigate losartan effects on reward reinforcement learning and the underlying neural mechanisms. In a double-blind, between-subject, placebo-controlled design, 60 healthy male subjects will be randomly assigned to receive single-dose losartan (50 mg) or placebo, 90 minutes before performing a probabilistic reinforcement learning task during fMRI.
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Parallel
- Primary Purpose
- Basic Science
- Masking
- Double (Participant, Investigator)
Eligibility Criteria
- Ages
- 18 Years to 30 Years (Adult)
- Sex
- Male
- Accepts Healthy Volunteers
- Yes
Inclusion Criteria
- •Healthy subjects without past or current psychiatric or neurological disorders
- •Right-handedness
- •Normal or corrected-normal version
Exclusion Criteria
- •History of head injury
- •Medical or psychiatric illness
- •Hypertension
- •General cardio-vascular alteration or diseases
- •Allergy against medications
- •Visual or motor impairments
- •Claustrophobia
- •Drug addiction
- •Nicotine dependence
- •FMRI contradictions
Arms & Interventions
Losartan group
Drug: Losartan
Intervention: Losartan (Drug)
Placebo group
Drug: Placebo Oral Tablet
Intervention: Placebo oral tablet (Drug)
Outcomes
Primary Outcomes
BOLD-level activity as assessed by fMRI during the learning phase
Time Frame: 90 minutes to 110 minutes after treatment
During the paradigm subjects will learn the reward properties of stimuli via the presentation of trial-wise feedback. The neural activation during the prediction of positive and negative outcome feedback will be assessed by functional magnetic resonance imaging (fMRI), particularly in prefrontal and subcortical regions. The effects of treatment will be determined by comparing the losartan- and placebo-treated groups.
BOLD-level activity as assessed by fMRI during the learning transfer phase
Time Frame: 111 minutes to 120 minutes after treatment
Following the initial learning phase subjects learning transfer will be examined by asking subjects to choose between stimuli with high versus low reward probabilities. The neural activation during correct responses will be assessed by functional magnetic resonance imaging (fMRI), particularly in prefrontal and subcortical regions. The effects of treatment will be determined by comparing the losartan- and placebo-treated groups.
Secondary Outcomes
- Learning rate for positive and negative outcomes(90 minutes to 110 minutes after treatment)
- Choice accuracy for the stimulus with the high reward probability during the learning phase(90 minutes to 110 minutes after treatment)
- Choice accuracy during the learning transfer phase(111 minutes to 120 minutes after treatment)
Investigators
Benjamin Becker
Professor
University of Electronic Science and Technology of China