Novel in Vivo Synaptic Imaging in Experienced Meditators

Inclusion Criteria: * Age 28-70 years * Voluntary, written, informed consent * Physically healthy by medical history, physical, ECG and laboratory examinations * At least 10 years and 5,000 hours of regular meditation practice * For females, non-lactating, no longer of child-bearing potential or agree to practice effective contraception during the study, as well as a negative serum pregnancy (β-HCG) test at screening, and negative urine pregnancy on PET scanning days. Exclusion Criteria: * A history of significant psychiatric, medical (e.g., cardiovascular, renal) or neurological (e.g., cerebrovascular, seizure, traumatic brain injury) illness that is unstable and/or might affect the study objectives. * Current or history of substance dependence (e.g., alcohol, nicotine, opiates, sedative hypnotics, etc.) * Subjects with history of prior radiation exposure for research purposes within the past year such that participation in this study would place them over FDA limits for annual radiation exposure. This guideline is an effective dose of 5 rem received per year. * Subjects with current, past or anticipated exposure to radiation in the work place within one year of proposed research PET scans that in combination with the study tracer would result in a cumulative exposure that exceeds recommended exposure limits. * Medical contraindications to participation in a magnetic resonance imaging procedure (e.g., ferromagnetic implants/foreign bodies, claustrophobia, cardiac pacemake…