Caffeine-RACCaffeine's Impact on Adenosine-Dopamine Receptor Interactions in Healthy Individuals
Caffeine (200 mg)
+ Placebo
Basic Science Study
Summary
Study start date: May 17, 2023
Actual date on which the first participant was enrolled.This study explores the interaction between two types of brain receptors, adenosine 2A receptors (A2AR) and dopamine D2 receptors (D2R), and how these interactions affect learning and behavior. Researchers are interested in understanding how caffeine, which blocks A2AR, influences these receptor interactions and affects cognitive processes like reinforcement learning. The study involves twelve healthy young adults and aims to deepen the understanding of how these molecular interactions influence behaviors associated with dopamine-related conditions, such as psychosis. Participants will undergo two different conditions: one with caffeine and one with a placebo. Before these conditions, they must avoid caffeine, alcohol, and drugs for six days and maintain a regular sleep schedule. On the seventh day, they receive either caffeine or a placebo before undergoing brain scans using PET and fMRI technology. These scans help measure the availability of D2/D3 receptors and brain activity during tasks involving reinforcement learning. The study hypothesizes that caffeine will enhance brain activity related to rewards and that this increased activity will correspond with changes in receptor availability.
Protocol
This section provides details of the study plan, including how the study is designed and what the study is measuring.12 patients to be enrolled
Total number of participants that the clinical trial aims to recruit.Basic Science Study
Eligibility
Researchers look for people who fit a certain description, called eligibility criteria: person's general health condition or prior treatments.Any sex
Biological sex of participants that are eligible to enroll.From 18 to 45 Years
Range of ages for which participants are eligible to join.Healthy volunteers allowed
If individuals who are healthy and do not have the condition being studied can participate.Criteria
Inclusion Criteria: * Age ≥ 18 and ≤ 45. * Habitual caffeine intake ≥ 100 mg and ≤ 450 mg daily. * Non-smokers. * Clinically healthy. * Have normal vision or corrected to normal vision. Exclusion Criteria: * Pregnant or lactating women. * Women using hormonal contraceptives. * BMI \< 18.5 or \> 29.9 * Sleep disturbance or extreme chronotype. * Urine test positive on one of the following substances: benzoylecgonine, morphine, d-Methamphetamine, d-Amphetamine, Benzodiazepines, Secobarbital, Methadone, Buprenorphine Glucuronide, Nortriptyline, MDMA, Oxycodone, PCP, Propoxyphene, and Cannabis/THC * Diagnosis of depression, anxiety, psychosis, or neurologic disorders in the last 5 years. * Heart or cardiovascular diseases. * Diabetes or other metabolic diseases. * Under chronic medications, for instance, painkiller and steroid. * Allergy to lactose (main ingredient of blank control dose) * Incapable to operate the tasks or comprehend the study information in English. General MRI and PET safety exclusion criteria for all subjects: * Metallic foreign bodies such as cardiac pacemakers, perfusion pumps, aneurysm clips, metallic tattoos anywhere on the body, tattoos near the eye. * Pre-existing medical conditions including a likelihood of developing seizures or claustrophobic reactions * Inability to lie flat on scanner bed for about 90 min as assessed by physical examination and medical history (e.g. arthritis) * Recent exposure to radiation (i.e., PET from other research studies) that, when combined with this study, would be above the allowable limits * Pregnancy or breastfeeding: A negative serum or urine pregnancy test is required on the day of the PET procedure * Body weight of \> 300 lbs (weight limit of the MRI scanner table)
Study Plan
Find out more about all the medication administered in this study, their detailed description and what they involve.2 intervention groups are designated in this study
50% chance of being blinded to the placebo group
Treatment Groups
Group I
ExperimentalGroup II
PlaceboStudy Objectives
Primary Objectives
Secondary Objectives
Study Centers
These are the hospitals, clinics, or research facilities where the trial is being conducted. You can find the location closest to you and its status.This study has 1 location
Athinoula A. Martinos Center for Biomedical Imaging
Charlestown, United StatesOpen Athinoula A. Martinos Center for Biomedical Imaging in Google Maps