A Brain Imaging Study to Assess the Binding of MSP-2020 to Serotonin 5-HT2A Receptors in Healthy Male Adults

This is a brain imaging study testing a new radioactive tracer called MSP-2020 in healthy adult men to see how well it binds to a specific brain receptor called serotonin 5-HT2A. These types of studies help researchers understand how new drugs or compounds interact with brain chemistry, which is important for developing treatments for mental health conditions. **You may be eligible if...** - You are a healthy adult male - Your BMI is between 18 and 32 - You are in good general health confirmed by medical history, physical exam, ECG, blood tests, and an echocardiogram - You are able to stay at the clinical research unit for up to 4 days **You may NOT be eligible if...** - You have a first-degree relative (parent, sibling) with schizophrenia, psychotic disorder, or bipolar disorder - You have a known allergy to the tracer used in the scan - You have metal implants, a pacemaker, or other conditions that prevent you from having an MRI - You have had prior radiation exposure from research studies - You have claustrophobia or are unable to lie still for the MRI scan Talk to your doctor to see if this trial is right for you.