Characterizing the HIV Brain during Rest using Neuroimaging
Recent studies have shown that 35-70% of patients infected with the human immunodeficiency virus type one (HIV) exhibit at least some form of neuropsychological impairment. These impairments are generally referred to as HIV-associated neurocognitive disorders (HAND) and are formally categorized into three levels. Importantly, although neuropsychological studies have shown that HAND affects a wide array of cognitive functions, a formal diagnosis is still based on the exclusion of opportunistic infections and other common ailments, as no specific tests or biomarkers are currently available. The primary goal in the current study was to use magnetoencephalography (MEG), which is a noninvasive and direct measure of neural activity with millisecond temporal resolution and millimeter spatial precision, to identify cortical regions where there was reduced neuronal firing in HIV-infected participants compared with controls, and to decipher whether activity in these regions was predictive of neuropsychological functioning. Reductions in neural activity likely indicate reduced neuronal synchronization within specific brain areas. Potentially, such functional indices of neural activity may be more sensitive to early cortical changes than structural-based measures, and thus provide improved options for early detection of HAND.
The study team used MEG imaging to measure neural activity during rest (i.e., when the participants were not engaged in any task) in 15 HIV-infected patients and a matched group of 15 uninfected controls. Their primary findings were that HIV-infected persons exhibited decreased beta (14-30 Hz) oscillations in several brain regions, including the supplementary motor area, paracentral lobule, posterior cingulate, and bilateral regions of the superior parietal lobule relative to healthy controls. Beta oscillations in the posterior cingulate, a critical component of the default mode network, were also positively correlated with patient scores on the memory recall aspect of the Hopkins Verbal Learning Test-Revised. These results demonstrate that chronic HIV infection does not uniformly disturb cortical function, and that neuronal populations in dorso-medial motor and parietal cortices are especially affected. These findings also suggest that resting-state MEG recordings may hold significant promise as a functional biomarker for identifying HAND and monitoring disease progression.
The full abstract of the paper, as well as a link to the full text can be found here.
The study of the biological basis of behavior is one of the most rapidly growing
areas of life sciences, reflecting the importance of the fundamental and applied interest in how neurons work on an individual basis, and how collections of neurons mediate behavior and cognition.
The College of Arts and Sciences at UNO has established the first undergraduate neuroscience degree program in the Nebraska system to educate students bound for graduate programs in neuroscience as well as various careers in the health or health-related fields.
Students working toward completion of this degree will benefit from the expertise of existing faculty in the UNO departments of Biology and Psychology along one of two tracks: Molecular and Cellular Neuroscience or Integrative Behavioral Science.
An undergraduate major in neuroscience will place students in the position of
moving into one of multiple career trajectories upon completion of the degree.
First, graduates of the program will be in an excellent position to immediately and successfully be recruited by one of the more than 200 graduate programs in neuroscience and related areas, and pursue advanced degrees. These opportunities include working with faculty at UNMC’s growing training programs and opportunities. The newly established Department of Pharmacology and Experimental Neuroscience at UNMC brings together experts in neuropharmacology with those with expertise in neurodegenerative diseases, and new and exciting graduate programs are likely to emerge from this new department. Neuroscience and related disciplines constitute among the best funded and active programs at UNMC. The Center for Neurovirology and Neurodegenerative Disorders (CNND) and the associated Neuroscience Research Training Program (NRTP) at UNMC constitute an important employment and training outlet for graduates of an undergraduate neuroscience major.
Second, graduates from either of the proposed neuroscience tracks would have most or all of the required courses for admission to medical schools, veterinary programs, and a host of other health-related professional programs.
Third, graduates of the neuroscience major will possess intellectual and methodological skill-sets that will make them highly attractive for laboratory technicians and assistants in local, regional, and national university and medical school laboratories.
Fourth, the growing emphasis on pharmaceutical agents that affect psychological function is driving employment in corporate pharmaceutical firms, for which graduates of the neuroscience major would be competitive.
Finally, students will emerge from the major with the ability to think across disciplines, to formulate questions and seek answers, to interpret data and draw conclusions, and to effectively communicate the outcome of these processes to a target audience. This suite of skills will make neuroscience majors eligible for a variety of career opportunities that are outside of the discipline of neuroscience.