Entity

Time filter

Source Type


Kelly R.,Georgia Institute of Technology | Mizelle J.C.,Georgia Institute of Technology | Mizelle J.C.,Center for Visual and Neurocognitive Rehabilitation | Wheaton L.A.,Georgia Institute of Technology
Neuropsychologia | Year: 2015

Prior work has demonstrated that perspective and handedness of observed actions can affect action understanding differently in right and left-handed persons, suggesting potential differences in the neural networks underlying action understanding between right and left-handed individuals. We sought to evaluate potential differences in these neural networks using electroencephalography (EEG). Right- and left-handed participants observed images of tool-use actions from egocentric and allocentric perspectives, with right- and left-handed actors performing the actions. Participants judged the outcome of the observed actions, and response accuracy and latency were recorded. Behaviorally, the highest accuracy and shortest latency was found in the egocentric perspective for right- and left-handed observers. Handedness of subject showed an effect on accuracy and latency also, where right-handed observers were faster to respond than left-handed observers, but on average were less accurate. Mu band (8-10. Hz) cortico-cortical coherence analysis indicated that right-handed observers have coherence in the motor dominant left parietal-premotor networks when looking at an egocentric right or allocentric left hands. When looking in an egocentric perspective at a left hand or allocentric right hand, coherence was lateralized to right parietal-premotor areas. In left-handed observers, bilateral parietal-premotor coherence patterns were observed regardless of actor handedness. These findings suggest that the cortical networks involved in understanding action outcomes are dependent on hand dominance, and notably right handed participants seem to utilize motor systems based on the limb seen performing the action. The decreased accuracy for right-handed participants on allocentric images could be due to asymmetrical lateralization of encoding action and motoric dominance, which may interfere with translating allocentric limb action outcomes. Further neurophysiological studies will determine the specific processes of how left- and right-handed participants understand actions. © 2015 Elsevier Ltd. Source


Chasan J.E.,Emory University | Delaune B.,Center for Visual and Neurocognitive Rehabilitation | Maa A.Y.,Emory University | Maa A.Y.,Atlanta Medical Center | And 2 more authors.
JAMA Ophthalmology | Year: 2014

IMPORTANCE: Telemedicine is a useful clinical method to extend health care to patients with limited access. Minimal information exists on the subsequent effect of telemedicine activities on eye care resources. OBJECTIVE: To evaluate the effect of a community-based diabetic teleretinal screening program on eye care use and resources. DESIGN, SETTING, AND PARTICIPANTS: The current studywas a retrospective medical record review of patients who underwent diabetic teleretinal screening in the community-based clinics of the Atlanta Veterans Affairs Medical Center from October 1, 2008, through March 31, 2009, and who were referred for an ophthalmic examination in the eye clinic. EXPOSURES: Clinical medical records were reviewed for a 2-year period after patients were referred from teleretinal screening. The following information was collected for analysis: patient demographics, referral and confirmatory diagnoses, ophthalmology clinic visits, diagnostic procedures, surgical procedures, medications, and spectacle prescriptions. MAIN OUTCOMES AND MEASURES: The accuracy between referring and final diagnoses and the eye care resources that were used in the care of referred patients. RESULTS: The most common referral diagnoses were nonmacular diabetic retinopathy (43.2%), nerve-related disease (30.8%), lens or media opacity (19.1%), age-related macular degeneration (12.9%), and diabetic macular edema (5.6%). The percentage of agreement among these 5 visually significant diagnoses was 90.4%, with a total sensitivity of 73.6%. Diabetic macular edema required the greatest number of ophthalmology clinic visits, diagnostic tests, and surgical procedures. Using Medicare cost data estimates, the mean cost incurred during a 2-year period per patient seen in the eye clinic was approximately $1000. CONCLUSIONS AND RELEVANCE: Although a teleretinal screening program can be accurate and sensitive for multiple visually significant diagnoses, measurable resource burdens should be anticipated to adequately prepare for the associated increase in clinical care. Copyright 2014 American Medical Association. All rights reserved. Source


Wei Z.Z.,Emory University | Wei Z.Z.,Center for Visual and Neurocognitive Rehabilitation | Gu X.,Emory University | Ferdinand A.,Emory University | And 6 more authors.
Cell Transplantation | Year: 2015

Neonatal stroke is a major cause of mortality and long-term morbidity in infants and children. Currently, very limited therapeutic strategies are available to protect the developing brain against ischemic damage and promote brain repairs for pediatric patients. Moreover, children who experienced neonatal stroke often have developmental social behavior problems. Cellular therapy using bone marrow mesenchymal stem cells (BMSCs) has emerged as a regenerative therapy after stroke. In the present investigation, neonatal stroke of postnatal day 7 (P7) rat pups was treated with noninvasive and brain-specific intranasal delivery of BMSCs at 6 h and 3 days after stroke (1 × 106cells/animal). Prior to transplantation, BMSCs were subjected to hypoxic preconditioning to enhance their tolerance and regenerative properties. The effects on regenerative activities and stroke-induced sensorimotor and social behavioral deficits were specifically examined at P24 of juvenile age. The BMSC treatment significantly reduced infarct size and blood–brain barrier disruption, promoted angiogenesis, neurogenesis, neurovascular repair, and improved local cerebral blood flow in the ischemic cortex. BMSC-treated rats showed better sensorimotor and olfactory functional recovery than saline-treated animals, measured by the adhesive removal test and buried food finding test. In social behavioral tests, we observed functional and social behavioral deficits in P24 rats subjected to stroke at P7, while the BMSC treatment significantly improved the performance of stroke animals. Overall, intranasal BMSC transplantation after neonatal stroke shows neuroprotection and great potential as a regenerative therapy to enhance neurovascular regeneration and improve functional recovery observed at the juvenile stage of development. © 2015 Cognizant Comm. Corp. Source


Wei Z.Z.,Emory University | Wei Z.Z.,Center for Visual and Neurocognitive Rehabilitation | Yu S.P.,Emory University | Yu S.P.,Center for Visual and Neurocognitive Rehabilitation | And 7 more authors.
Cellular and Molecular Neurobiology | Year: 2014

Stem cell transplantation therapy has provided promising hope for the treatment of a variety of neurodegenerative disorders. Among challenges in developing disease-specific stem cell therapies, identification of key regulatory signals for neuronal differentiation is an essential and critical issue that remains to be resolved. Several lines of evidence suggest that JNK, also known as SAPK, is involved in neuronal differentiation and neural plasticity. It may also play a role in neurite outgrowth during neuronal development. In cultured mouse embryonic stem (ES) cells, we test the hypothesis that the JNK pathway is required for neuronal differentiation. After neural induction, the cells were plated and underwent differentiation for up to 5 days. Western blot analysis showed a dramatic increase in phosphorylated JNKs at 1-5 days after plating. The phosphorylation of JNK subsequently induced activation of STAT1 and STAT3 that lead to expressions of GAP-43, neurofilament, βIII-tubulin, and synaptophysin. NeuN-colabelled with DCX, a marker for neuroblast, was enhanced by JNK signaling. Neuronal differentiation of ES cells was attenuated by treatment with SP600125, which inhibited the JNK activation and decreased the activation of STAT1 and STAT3, and consequently suppressed the expressions of GAP-43, neurofilament, βIII-tubulin, and the secretion of VEGF. Data from immunocytochemistry indicated that the nuclear translocation of STAT3 was reduced, and neurites of ES-derived neurons were shorter after treatment with SP600125 compared with control cells. These results suggest that the JNK-STAT3 pathway is a key regulator required for early neuronal differentiation of mouse ES cells. Further investigation on expression of JNK isoforms showed that JNK-3 was significantly upregulated during the differentiation stage, while JNK-1 and JNK-2 levels decreased. Our study provided interesting information on JNK functions during ES cell neuronal differentiation. © 2014 Springer Science+Business Media. Source


McGregor K.M.,Center for Visual and Neurocognitive Rehabilitation | McGregor K.M.,Emory University | Nocera J.R.,Center for Visual and Neurocognitive Rehabilitation | Nocera J.R.,Emory University | And 8 more authors.
Frontiers in Aging Neuroscience | Year: 2013

Physical fitness has been long associated with maintenance and improvement of motor performance as we age. In particular, measures of psychomotor speed and motor dexterity tend to be higher in physically fit aging adults as compared to their sedentary counterparts. Using functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS), we explored the patterns of neural activity that may, in part, account for differences between individuals of varying physical fitness levels. In this study, we enrolled both sedentary and physically fit middle age (40-60) and younger (18-30) adults and measured upper extremity motor performance during behavioral testing. In a follow-up session, we employed TMS and fMRI to assess levels of interhemispheric communication during unimanual tasks. Results show that increased physical fitness is associated with better upper extremity motor performance on distal dexterity assessments and increased levels of interhemispheric inhibition in middle age adults. Further, the functional correlates of changes of ipsilateral activity appears to be restricted to the aging process as younger adults of varying fitness levels do not differ in hemispheric patterns of activity or motor performance. We conclude that sedentary aging confers a loss of interhemispheric inhibition that is deleterious to some aspects of motor function, as early as midlife, but these changes can be mediated by chronic engagement in aerobic exercise. © 2013 McGregor, Nocera, Sudhyadhom, Patten, Manini, Kleim, Crosson and Butler. Source

Discover hidden collaborations