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OBJECTIVE Investigating consequences of early or late antiretroviral therapy (ART) initiation in infancy on young brain development using magnetic resonance spectroscopy. DESIGN Most pediatric HIV/ART-related neurological studies are from neuropsychological/clinical perspectives. Magnetic resonance spectroscopy can elucidate the mechanisms underpinning neurocognitive outcomes by quantifying the brain's chemical condition through localized metabolism to provide insights into health and development. METHODS Basal ganglia metabolite concentrations were assessed in thirty-eight 5-year-old HIV-infected children previously participating in a randomized trial comparing early limited ART to deferred continuous ART, as well as 15 uninfected controls (12 HIV exposed). Metabolite levels were compared between 26 infected children who initiated ART at/before 12 weeks and 12 who initiated afterward, and were correlated with clinical HIV and treatment-related measures. RESULTS HIV-infected children initiating ART after 12 weeks had lower creatine, choline and glutamate (P

OBJECTIVE As ~40% of persons with HIV also suffer neurocognitive decline, we sought to assess metabolic dysfunction in the brains of simian immunodeficiency virus (SIV)-infected rhesus macaques, an advanced animal model, in structures involved in cognitive function. We test the hypothesis that SIV-infection produces proton-magnetic resonance spectroscopic imaging (H-MRSI)-observed decline in the neuronal marker, N-acetylaspartate (NAA), and elevations in the glial marker, myo-inositol (mI), and associated creatine (Cr) and choline (Cho) in these structures. DESIGN Pre- and 4-6 weeks post-SIV infection (with CD8 T-lymphocyte depletion) was monitored with T2-weighted quantitative MRI and 16×16×4 multivoxel H-MRSI (TE/TR = 33/1400 ms) in the brains of five rhesus macaques. METHODS Exploiting the high-resolution H-MRSI grid, we obtained absolute, cerebrospinal fluid partial volume-corrected NAA, Cr, Cho and mI concentrations from centrum semiovale, caudate nucleus, putamen, thalamus and hippocampus regions. RESULTS Pre- to post-infection mean Cr increased in the thalamus: 7.2±0.4 to 8.0±0.8 mmol/l (+11%, P