SV2A & TSPO PET Imaging Measures to Reveal Mechanisms of HIV Neuropathogenesis During Antiretroviral Therapy

PLWH Inclusion Criteria: * Voluntary, written, informed consent (signed and dated) * For females, a negative urine or serum pregnancy (HCG) test at screening and on each scan day before initiation of any scan procedures. * HIV infection on cART with documented viral suppression for at least one year. Plasma viral suppression will be defined as no more than one viral load * Test above 20 HIV RNA cps/mL in the year prior to screening and no HIV RNA tests above 200 cps/mL in the same span. * Willingness to participate in MRI, PET, phlebotomy, and Neuropsychological Testing (NPT) Assessments \& Surveys. PLWH Exclusion Criteria: * Active substance dependence (e.g., heroin, alcohol, cocaine, sedative hypnotics, methamphetamine) as determined by the standardized Behavioral Assessments. * A history of significant non-HIV related neurological illness (e.g., cerebrovascular, seizures, traumatic brain injury). * Medical contraindications to the administration of radioactivity (e.g., prior radiation exposure within the past year from research, or from workplace exposure, that in combination with the planned scans would exceed the FDA limit for annual radiation exposure). * Medical contraindications to participation in a magnetic resonance imaging procedure (e.g., ferromagnetic implants/foreign bodies, claustrophobia, cardiac pacemaker, prosthetic valve, otologic implant, etc.). * History of a bleeding disorder, low platelet count, or are currently taking anticoagulants (such as Coumadin, Heparin, Pradaxa, Xarelto). HIV - Inclusion Criteria: * Voluntary, written, informed consent (signed and dated) * For females, a negative urine or serum pregnancy (HCG) test at screening and on each scan day before initiation of any scan procedures. * Willingness to participate in phlebotomy, NPT Assessments \& Surveys, MRI, and PET. * Physically healthy by medical history, physical, neurological, and laboratory examinations, as judged by the principal investigator. * Have a negative test for HIV on file within the last three months or willing to have an HIV test in the current study. HIV- Exclusion Criteria: * Active substance dependence (e.g., heroin, alcohol, cocaine, sedative hypnotics, methamphetamine) as determined by the standardized Behavioral Assessments. * A history of significant neurological illness (e.g., cerebrovascular, seizures, traumatic brain injury). * Medical contraindications to the administration of radioactivity (e.g., prior radiation exposure within the past year, from research, or from workplace exposure, that in combination with the planned scans would exceed the FDA limit for annual radiation exposure) * Medical contraindications to participation in a magnetic resonance imaging procedure (e.g., ferromagnetic implants/foreign bodies, claustrophobia, cardiac pacemaker, prosthetic valve, otologic implant, etc. * History of a bleeding disorder or are currently taking anticoagulants (such as Coumadin, Heparin, Pradaxa, Xarelto