Clinical Research Directory

* INCLUSION CRITERIA: 1. Male or females. 2. Young group (18-40 years of age) 3. Older group (\>40 years of age) 4. Ability to provide written informed consent EXCLUSION CRITERIA: 1. Pregnant and/or breast feeding. Females of childbearing potential must have negative urine pregnancy test and not be currently breastfeeding. Post-menopausal or surgically sterile (tubal ligation or hysterectomy) females satisfy these criteria. 2. Positive urine drug test for controlled substances (cocaine, methamphetamine, amphetamines, opioids, cannabinoids, benzodiazepines and barbiturates) on each visit involving imaging studies and/or neuropsychological assessment. 3. Head trauma with loss of consciousness for more than 30 minutes as determined by self-report and/or medical history. 4. Subjects with problematic insomnia as determined by self-report (reports having trouble sleeping on most days). 5. Subjects with any of the following: narcolepsy, obstructive sleep apnea (OSA) and/or abnormal sleeping patterns (including but not limited to those who use a CPAP machine, sleeping during the day, using medication to fall asleep, sleeps less than 5 hours per night, night shift workers) as determined by self-report and/or medical history. 6. Use, in the past two weeks, of psychoactive medications (four weeks for fluoxetine) or medications that may affect brain function (including but not limited to opioid analgesics, antidepressants, antipsychotics, benzodiazepines and barbiturates, stimulants) as determined by self-report and/or medical history. 7. Current DSM 5 diagnosis of affective disorder, addiction (other than nicotine of caffeine), PTSD, or schizophrenia. 8. Individuals with cognitive impairment as identified with a score of lower than 24 in the MMSE will be excluded. Further, individuals with impairment sufficient to affect consent capacity even if MMSE is less than 24 will be excluded. We will consult the Ability to Consent Assessment Team (ACAT) in those whose capacity to consent may be questionable. 9. Severe medical problems that can permanently impact brain function (e.g., problems of the CNS; cardiovascular; metabolic, autoimmune, endocrine) as determined by history and clinical exam. 10. Individuals with a medical history of a neurodegenerative disease. 11. Heavy alcohol users. Heavy alcohol users are those individuals who consume more than 5 drinks in one seating (if males) or more than 4 drinks in one seating (if females) more than twice a week will be excluded. 12. Uncontrolled hypertension. 13. Presence of ferromagnetic objects in the body that are contraindicated for MRI of the head (including but not limited to pacemakers or other implanted electrical devices, brain stimulators, some types of dental implants, aneurysm clips, metallic prostheses, permanent eyeliner, implanted delivery pump, or shrapnel fragments) or fear of enclosed spaces as determined by the self-report checklist. 14. Fear of enclosed spaces (claustrophobia) as determined by self-report and medical history. 15. Cannot lie comfortably flat on the back for up to 2 hours in the MRI scanner as determined by self-report. 16. Body weight \> 250 kg. This is the upper limit that the bed of the MR scanner can accommodate (clinical exam). 17. Have had previous radiation exposure (from X-rays, PET scans, or other exposure) that, with the exposure from this study, would exceed NIH annual research limits as determined by medical history and physical exam. 18. Study investigators and staff, as well as their superiors, subordinates and immediate family members (adult children, spouses, parents, siblings).