HIV Dementia Mechanism Discovered, Finding may lead to new therapies

In a linked study, Niyati Parekh, Ph.D., R.D., of the University of the Medicine and Dentistry of New Jersey, New Brunswick, and the University of Wisconsin-Madison, and colleagues analyzed background from 7,752 individuals (including 11 percent with AMD) who were cog of the National Cialis Professional Pills and Nutrition Examination Survey, a large study designed to epitomize the complete U.S. population. Participants were enrolled in the study involving 1988 and 1994. They had biological partial view that integrated blood and urine sample, photographs of the retinas, and interview and questionnaire in profit to sociodemographics, lifestyle conduct and food intake.

"This study unambiguously demonstrate that HIV contamination damages dopamine-associated psyche cell, and make available a pathway for emergent more important treatment," says National Institute with the side of Drug Abuse (NIDA) Director Nora Volkow, co-investigator, who work on the study while at Brookhaven Lab.

Using positron energy tomography (PET), a brain-scanning technique, Wang and colleagues look at the brain of 15 HIV-positive study volunteers, whichever of whom have symptom of dementia, and 13 HIV-negative volunteers. The intention of the scan be to initiate the being there of dopamine transporters and dopamine receptors.

Dopamine transporters, found on the terminal of some brain cells (neurons), recycle dopamine, a brain chemical that send summon involving the cells. Dopamine receptors be "docking ports" on the delivery neurons. Dopamine be associated with satisfaction and pay and is also vital for advancement; in short supply level are found in stipulations such by finances of Parkinson's disease. Decreased dopamine transporters hint neuron desecrate and deflate levels of functional dopamine neurons, moreover as decrease in the liberate of dopamine.

Prior to brain scan, all volunteer was given an immunisation try to make an impression a radiotracer, a radioactive chemical "tag" designed to "light up" activate area of the brain. The PET camera pick in the air the radioactive signal and measures the jumbo and situation of the tracer. Two hours after the first scan, each volunteer was given a second radiotracer, and his/her brain was scan again. The first scan looked specifically for the presence of dopamine receptors, and the second search for dopamine transporters.

The researchers found that HIV-positive patients with, but not those in requirement dementia, had to a large extent lower dopamine haulier levels in the putamen and ventral striatum, the brain region containing the furthermost transporters, equate with HIV-negative volunteers. Higher levels of HIV virus correlated with lower transporter levels in the caudate - part of a set of the striatum - and in the putamen. Dopamine receptor levels demonstrate individual kind decreases in HIV-positive volunteers.

"These findings put forward that HIV patients with dementia may plus from dopamine-enhancing treatments, particularly those patients with more feisty cognitive motor deficit," says Wang.

"Studies embrace shown, on the contrary, that some of these agents may truly exacerbate HIV-induced neurotoxicity, but antioxidants may clog up this contrivance. Further study should focus on adjunctive approach muddle up drugs in both classes." "Viral suppression appear to correlate with smaller digit injury to the dopamine group," Wang continue. "Because of this correlation, wished-for studies should make out whether viral suppression after antiretroviral treatment can lead to rescue of deficits in the dopamine system." This study was fund by the Office of Biological and Environmental Research inside the U.S. Department of Energy's Office of Science and the National Institute on Drug Abuse (NIDA). All research was conduct at Brookhaven Lab; scientists now at NIDA, the National Institute on Alcohol Abuse and Alcoholism, and the University of Hawaii contribute to the study.