IMMEDIATE RELEASE: November 19, 2008
Georgetown University/Georgetown University Medical Center Researchers Presented More than 100 Scientific Abstracts at Neuroscience 2008
Research highlights included how we see faces in our dreams, understanding how young and old adults learn, helping stroke survivors speak using fMRI, an explanation about autism and facial recognition
Washington, DC -- Researchers from Georgetown University and Georgetown University Medical Center’s departments of neuroscience, psychology, physiology and biophysics presented more than 100 research abstracts at the Society for Neuroscience’s 38th annual meeting, November 15 -19 at the Walter E. Washington Convention Center in Washington.
Abstracts covered a broad array of topics in the area of neuroscience including learning, facial recognition, autism, traumatic brain injury, and Parkinson’s disease.
I Saw Your Face in My Dreams
Where do the faces we see in our dreams and “in our head” while thinking about an individual come from? Researchers in the GUMC Department of Neuroscience have shown for the first time that neurons tuned to the sight of a person’s face also respond to images seen in memory – and possibly dreams.
Using functional Magnetic Resonance Imaging (fMRI) to study brain activity in a group of participants, they have found evidence that these images arise from activation of the same nerve cells that once “saw” the real person. So the image seen in dreams about a father long gone, and the face that is conjured up while remembering that father, appear to involve the re-firing of neurons that are specifically tasked with seeing and recognizing dad, the researchers say.
The investigators have long studied face recognition patterns in the brain, and had earlier discovered that while the “Fusiform Face Area” (FFA) of the brain contains millions of neurons, each “face neuron” appears to respond only to a small set of faces similar to its “preferred” face. Thus, when dad is seen or remembered, only neurons that prefer “dad-like” faces respond strongly. Other neurons recognize – and also help remember – mom’s face.
Abstract title: Imagery and perception of individual faces activate joint and highly specific neural representations - an fMRI adaptation study
Authors: M. RIESENHUBER, X. JIANG; Dept Neurosci, Georgetown Univ. Med. Ctr., Washington, DC
Telling Faces Apart – The Challenge Isn’t the Same for All with Autism
For the first time, researchers in the GUMC Department of Neuroscience and Childrens National Medical Center have “looked” into the brains of individuals with autism spectrum disorders (ASD) to discover why there is such broad variability in face recognition abilities across the autism spectrum. Deficits in face recognition likely contribute to the difficulties in social interaction that are one of the defining features of ASD.
Using functional Magnetic Resonance Imaging (fMRI) adaptation techniques, a novel brain imaging method that probes neural processing more finely than conventional methods, they have found that, in some study participants with autism, neurons in an area of the brain known to be key to face recognition do not respond as selectively as in people without autism. Other autistic participants in contrast may be using different areas of the brain for the task, resulting in a decreased ability to tell faces apart.
Results from the study are considered preliminary, but they are the first to mechanistically link individual behavioral differences in ASD for a particular behavioral trait to differences in processing at the neuronal level. It may be that while the spectrum of autistic disorders often involve decreased ability to recognize faces, there are a number of ways this deficit can occur, and which varies across individuals. The investigators say that this finding may be helpful to provide more precise ways to characterize autism as well as a potential strategy for personalized treatment.
Abstract Title: The heterogeneity of face perception deficits in Autism Spectrum Disorder (ASD) might be caused by tuning differences of neurons in the Fusiform Face Area (FFA) - a pilot study
Authors: X. JIANG1, A. BOLLICH3, E. HYDER1, J. JAMES3, S. GOWANI5, V. BLANZ7, N. HADJIKHANI6,8, D. S. MANOACH5, W. GAILLARD4,2, M. RIESENHUBER1;
1Dept Neurosci, 2Dept Neurol, Georgetown Univ. Med. Ctr., Washington, DC; 3The Ctr. for Autism Spectrum Disorders, 4Dept Neurosci, Children's Natl. Med. Ctr., Washington, DC; 5Dept. of Psychiatry, 6Dept. of Radiology, Massachusetts Gen. Hosp., Boston, MA; 7Univ. of Siegen, Siegen, Germany; 8Swiss Federal Inst. of Technol., Lausanne,
Treating Traumatic Brain Injury Improves Cognition, Reduces Lesion
Traumatic brain injury (TBI) causes inflammation and loss of brain tissue, with significant functional consequences. An enzyme that plays a role in this inflammation and may be targeted for drug therapies is NADPH oxidase, which is expressed primarily by microglia (immune system cells) in the brain and produces toxic molecules that can damage brain cells. To determine if shutting down this enzyme will reduce inflammation and improve recovery after TBI, researchers in the Laboratory for the Study of Central Nervous System Injury tested a laboratory drug called diphenyleneiodonium (DPI) both on microglial cells in culture and in an animal model of this kind of brain injury.
Application of DPI to microglial cells in the laboratory resulted in significant reductions in activity of the cells, including production of the toxic chemical nitric oxide. When animals that were subjected to TBI were given DPI 30 minutes after injury, they demonstrated significant improvements in cognitive performance two weeks after injury and reductions in the size of the brain lesion three weeks after injury when compared to animals that did not receive treatment. Therefore, DPI and other drugs that are directed at NADPH oxidase may be key therapeutic targets for TBI treatment, the researchers say.
Abstract title: Diphenyleneiodonium reduces tissue damage and improves functional recovery after traumatic brain injury in mice
Authors: M. XIE, K. R. BYRNES, B. A. STOICA, A. I. FADEN;
Dept. of Neurosci, Georgetown Univ. Med. Ctr., Washington, DC
Teaching an Old (and Young) Dog New Tricks – Young and Old Adults Learn With Different Parts of the Brain
Young adults use a different part of their brains to learn than old adults do, even when both groups have learned equally well. The findings of a new study, while not surprising, could impact how older adults are taught to adapt to modern technologies such as PDAs or learning to use the computer.
“The new information might someday help physicians identify the difference between healthy adults and those suffering from pathological aging such as Alzheimer’s disease and Parkinson’s disease,” says the study’s lead author Jessie R. Simon, a doctoral candidate at Georgetown.
Abstract title: Neural basis of probabilistic sequence learning in again: an fMRI study
Authors: J. R. SIMON1, K. BARNES1, C. J. VAIDYA1,3, J. H. HOWARD, Jr4,1,2, D. V. HOWARD1;
1Psychology, 2Neurol., Georgetown Univ., Washington, DC; 3Children’s Res. Institute, Children’s Natl. Med. Ctr., Washington, DC; 4Catholic Univ., Washington, DC
Using fMRI to Tailor Stroke Treatment One Patient at a Time
Behavioral interventions for chronic stroke patients can work to remediate long-standing deficits, say researchers who used functional Magnetic Resonance Imaging (fMRI) to “watch” changes taking place in the brain of a 45-year-old stroke patient as she began to be able to read again.
The Cognitive Neuropsychology Lab in the Center for Aphasia Research and Rehabilitation at GUMC is one of the few labs that focuses on rehabilitation of language problems one year after stroke or brain injury, when many believe patients cannot recover lost functioning. In this study, researchers designed a treatment targeting a class of words that a stroke patient, who had otherwise recovered, still could not read, and they used fMRI to determine how activity in her brain associated with reading these words might change with therapy. After treatment, activity when viewing these words was found in areas more similar to those found in other studies of reading in control patients.
Abstract title: Processing of function words before and after behavioral treatment intervention: an fMRI case study
Authors: E. H. LACEY1, J. KURLAND2, M. A. TAGAMETS3, C. R. CORTES3, S. F. SNIDER1, S. N. LOTT1, R. B. FRIEDMAN1;
1Georgetown Univ., Washington, DC; 2Dept. of Communication Disorders, Univ. of Massachusetts Amherst, Amherst, MA; 3Univ. of Maryland at Baltimore, Baltimore, MD
Forestalling Parkinson’s Disease
Researchers in GUMC’s Department of Neuroscience are testing the notion that inflammation in the brain plays an important role in Parkinson’s disease (PD) years before symptoms occur. If true, development of the disease could be forestalled with use of specific anti-inflammatory agents.
In a series of cell culture and animal studies, the researchers found that a protein known as alpha-synuclein can activate microglia (immune cells in the brain), setting off a cascade of inflammatory responses. Alpha-synuclein plays a role in PD, although no one knows its precise function. Mutations in the gene that produces alpha-synuclein results in early-onset PD in humans, and the clumps of protein known as Lewy bodies found in the brains of older patients with PD are composed in part, of alpha-synuclein.
The researchers say their next step is to test therapeutic agents that mitigate this pro-inflammatory response to alpha-synuclein. They say they have a good lead on design of these drugs – their research has shown that the errant protein activates a specific receptor (CD36) on microglia. They are currently examining the use of one CD36 inhibitor in laboratory studies and plan to investigate others.
Abstract title: Direct activation of microglia by mutated Alpha-synuclein
Authors: *K. A. MAGUIRE-ZEISS1, X. SU2, H. J. FEDEROFF1;
1Dept Neurosci, Georgetown Univ. Med. Ctr., Washington, DC; 2Univ. of California San Francisco, San Francisco, CA
Thumbing Through the Brain’s Visual Word Dictionary
Successful reading requires the brain to correctly recognize printed individual words but it has been unclear how this occurs. To find out, researchers in the GUMC Laboratory for Computational Cognitive Neuroscience used functional MRI (fMRI) to map brain activity when participants read "real" words as well as novel or "pseudowords (never before seen combination of letters that follow the rules of how words are structured in English such as bleb or strab).
They found that in the visual object-recognition region of the brain, there is an area that appears to function like a "visual word dictionary". Neurons there seem to be specialized to process real words as whole-word units; they show far less selectivity for groups of letters that make up nonsense words. The findings may shed light on dyslexia, because other studies have shown lower activation in this brain region in people with this and other reading disorders. The study may provide a new way to detect, diagnose, and treat these disabilities.
Abstract title: Evidence for an orthographic lexicon in the ventral visual pathway
Authors: L. J. GLEZER, X. JIANG, M. RIESENHUBER;
Georgetown Univ., Washington, DC
Natural-Born Pain Relievers: Scientist Find Larger Role for Naturally Produced Analgesic
New information about the role of the amygdala region of the brain is helping researchers hone in on new strategies to treat pain. The amygdala region has recently been linked to the modulation of pain perception, in addition to its well-studied role in anxiety and fear disorders. In a new study, scientists explore the role of a newly recognized neurotransmitter (N-acetylaspartylglutamate or NAAG) in mediating analgesia by action in the amygdala region. Novel drugs that inhibit the breakdown of NAAG have been shown to be an analgesic when administered systemically, locally and centrally following inflammation in animal models of pain.
“We previously demonstrated that NAAG can play a role in analgesia and this may have implications for treatment of inflammatory, neuropathic and cancer pain. We’re now getting a better understanding NAAG’s role in the amygdala region which will help us learn more about its role in reducing pain perception as well as its general function in the central nervous system. In the longer term, this may aid in the design of a new class of drugs to treat pain and for this reason this research is supported by a grant from the National Institutes of Health,” says Mary O. Adedoyin, a doctoral candidate at Georgetown University.
Abstract title: The role of N-acetylaspartylglutamate in inflammatory pain
Authors: M. O. ADEDOYIN1, J. G. PARTRIDGE2, S. VICINI2, J. H. NEALE1;
1Biol. Dept., Georgetown Univ., Washington, DC; 2Biol. Dept., Georgetown Univ., Physiology and Biophysics Department
A New Look at Examining Rapid Object Recognition
Cell communication, or functional connectivity, is crucially important for normal functioning of the brain. It underlies the ability of the brain to integrate information which is processed in parallel by cell groups (circuits) widely distributed over the whole cortex of the brain. Researchers in the GUMC Center for Functional and Molecular Imaging use a novel technique to study functional connectivity of the brain called noninvasive optical imaging or Near-infrared Spectroscopy (NIRS). It measures blood supply in different areas of the brain using near-infrared light. Due to its inexpensiveness and compactness, investigators say this novel technology may provide a rapid, cost-efficient, sensitive and specific method to measure brain activity, which can be used in basic and clinical research.
In this study, they show that brain cells communicate to each other more intensively during rapid recognition of specific objects (targets) in complex images such as natural scenes. Investigators conclude their findings demonstrate the feasibility of utilizing optical imaging to study complex interactions between different brain structures during cognitive processes.
Abstract title: Functional connectivity in the cortex measured by near-infrared spectroscopy during rapid object recognition
Authors: A. V. MEDVEDEV1, J. KAINERSTORFER2, S. BORISOV1, J. VANMETER1;
1Dept Neurol, Georgetown Univ., Washington, DC; 2Dept. of Physics, Univ. of Vienna, Vienna, Austria
About Georgetown University Medical Center
Georgetown University Medical Center is an internationally recognized academic medical center with a three-part mission of research, teaching and patient care (through our partnership with MedStar Health). Our mission is carried out with a strong emphasis on public service and a dedication to the Catholic, Jesuit principle of cura personalis -- or "care of the whole person." The Medical Center includes the School of Medicine and the School of Nursing and Health Studies, both nationally ranked, the world-renowned Lombardi Comprehensive Cancer Center and the Biomedical Graduate Research Organization (BGRO), home to 60 percent of the university’s sponsored research funding.