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Nora Volkow

Publications and source records attributed to Nora Volkow.

9 recordsLinked to original sources
PubMed2006

Common human 5' dopamine transporter (SLC6A3) haplotypes yield varying expression levels in vivo.

1. Individuals display significant differences in their levels of expression of the dopamine transporter (DAT; SLC6A3). These differences in DAT are strong candidates to contribute to individual differences in motor, mnemonic and reward functions. To identify "cis"-acting genetic mechanisms for these individual differences, we have sought variants in 5' aspects of the human DAT gene and identified the haplotypes that these variants define. 2. We report (i) significant relationships between 5' DAT haplotypes and human individual differences in ventral striatal DAT expression assessed in vivo using [(11)C] cocaine PET and (ii) apparent confirmation of these results in studies of DAT expression in postmortem striatum using [(3)H] carboxyflurotropane binding. 3. These observations support the idea that cis-acting variation in 5' aspects of the human DAT/SLC6A3 locus contributes to individual differences in levels of DAT expression in vivo. 5' DAT variation is thus a good candidate to contribute to individual differences in a number of human phenotypes.

5' Flanking Region↗
PubMed2005

Exploiting temporal information in functional magnetic resonance imaging brain data.

Functional Magnetic Resonance Imaging(fMRI) has enabled scientists to look into the active human brain, leading to a flood of new data, thus encouraging the development of new data analysis methods. In this paper, we contribute a comprehensive framework for spatial and temporal exploration of fMRI data, and apply it to a challenging case study: separating drug addicted subjects from healthy non-drug-using controls. To our knowledge, this is the first time that learning on fMRI data is performed explicitly on temporal information for classification in such applications. Experimental results demonstrate that, by selecting discriminative features, group classification can be successfully performed on our case study although training data are exceptionally high dimensional, sparse and noisy fMRI sequences. The classification performance can be significantly improved by incorporating temporal information into machine learning. Both statistical and neuroscientific validation of the method's generalization ability are provided. We demonstrate that incorporation of computer science principles into functional neuroimaging clinical studies, facilitates deduction about the behavioral probes from the brain activation data, thus providing a valid tool that incorporates objective brain imaging data into clinical classification of psychopathologies and identification of genetic vulnerabilities.

Algorithms↗
PubMed2004

Nora Volkow: motivated neuroscientist.

Nora Volkow claims to have always been curious about the workings of the human brain. Even as a medical student in her native Mexico, she investigated animal behavior with the ultimate goal of understanding human motivation. Upon completing her medical studies, in the early 80s, she moved to the U.S. to take advantage of emerging neuroimaging technologies, first during her psychiatry residency at New York University and Brookhaven National Laboratory, and then as a faculty member at the University of Texas in Houston. In Houston, Volkow embarked on seminal studies into human drug use and the functioning brain, which she continued to pursue, again at Brookhaven, during the subsequent two decades. Volkow established herself as an eminent researcher and proponent of neuroscience, and her insights into the brain have greatly advanced our appreciation of human behavior and motivation. In 2003, she took up her present position as Director of the National Institute on Drug Abuse.

History, 20th Century↗