Linda Chao, PhD, is an Associate Adjunct Professor in the Department of Radiology and Biomedical Imaging and in the Department of Psychiatry at the University of California, San Francisco. Dr. Chao obtained her BS in Biological Science from the University of California, Davis in 1991, and she completed her PhD studies in Neuroscience from UCD in 1996. For the past 11-years, she has served as leader for the Psychiatry Block of the Interdepartmental Studies course 104, Brain, Mind and Behavior for first-year medical students.
Dr. Chao’s professional activities primarily consist of conducting basic research using neuropsychological and imaging techniques to characterize how normal aging, neurodegenerative processes, stress, and exposure to neurotoxins affect the brain and cognition. She has an ongoing project, funded by the Department of Veterans Affairs, that seeks to use cognitive tests, structural, and diffusion tensor imaging to examine the effects of low-level exposure to sarin on brain structure and brain function in Gulf War Veterans. Dr. Chao has another project that is funded by the US Army Military Operational Medicine Research Program. The purpose of this project is to investigate the links between post-traumatic stress disorder (PTSD) and dementia.
Dr. Chao serves as an Academic Editor for PlosOne and she has previously served as a reviewer for 26 scientific journals. Dr. Chao has 25 published articles and she has written 58 abstracts, 44 peer-reviewed articles, and 5 significant publications resulting from her research.
Industry Expertise (8)
Areas of Expertise (7)
University of California, Davis: Ph.D., Neuroscience
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Poor sleep quality linked to reduced brain gray matter in Gulf War vets
"Previous imaging studies have suggested that sleep disturbances may be associated with structural brain changes in certain regions of the frontal lobe," said lead author Linda Chao, associate adjunct professor in the Departments of Radiology and Biomedical Imaging and Psychiatry at the University of California, San Francisco. "The surprising thing about this study is that it suggests poor sleep quality is associated with reduced gray matter volume throughout the entire frontal lobe and also globally in the brain."...
Thomas Neylan, Daniela Kaufer, Steven Woodward, Duygu Tosun
Myelin-forming oligodendrocytes in the adult brain are responsible for highly plastic changes in brain myelination in response to new experiences and learning. Myelination in axons most likely evolved to improve conduction velocity, but in grey matter (GM) it reduces overall axonal sprouting and neuroplasticity. We hypothesized that across a continuum of symptom severity, human adults with higher PTSD symptoms related to adult trauma exposure will demonstrate higher myelin content in GM the hippocampus and other structures. We used T1w/T2w image intensity ratio to estimate the degree of GM myelination in veterans with (N= 19) and without (N= 19) PTSD. We found significantly more hippocampal myelin in PTSD+ than PTSD- veterans. (p=0.006, Mann-Whitney U-test. Furthermore, there was a positive correlation between current PTSD symptom severity and log-transformed estimates of hippocampal myelination in this (r = 0.47, p=0.003) and in another cohort of 32 subjects with adult-trauma exposure (r=0.51, p=0.003). Furthermore, GM myelin content was significantly and positively correlated with current CAPS score in frontal and temporal lobe over and above potentially confounding variables. Finally, higher GM myelin was associated with poorer recognition discriminability on the California Verbal Learning Test. The results suggest that maladaptive adult myelin development is a novel mechanism underpinning the structural brain abnormalities in PTSD. It represents a form of adaptive plasticity potentially has a far greater reach in the adult brain compared to other mechanisms such as adult neurogenesis. Adaptive myelination is a novel mechanism for understanding brain responses to trauma.
Despite the fact that many veterans returned from the 1991 Gulf War (GW) with complaints of memory difficulties, most neuropsychological studies to date have found little evidence of a correspondence between subjective and objective measures of cognitive function in GW veterans. However, if GW veterans complain about memory problems, it is likely that they experience memory problems in their daily lives. In this respect, it is notable that the past studies that have investigated the relationship between subjective and objective measures of cognitive function in GW veterans used composite measures to quantify subjective complaints and batteries of neuropsychological tests that assessed multiple domains to objectively measure cognitive function. The study's focus on memory was motivated by the suggestive evidence that subjective memory complaint may be a harbinger of further cognitive decline and increased risk for dementia. Materials and Methods: This study examined the association between subjective memory complaint (probed with single question: “Do you have difficulty remembering things?”) and performance on a single objective test of verbal learning and memory (i.e., California Verbal Learning Test, CVLT-II) in a sample of 428 deployed GW veterans. Results: GW veterans who endorsed memory difficulties performed more poorly on CVLT-II measures of total learning, retention, and delayed recall than GW veterans without subjective memory complaints (p < 0.001), even after accounting for demographic (e.g., age, sex, education) and clinical variables (e.g., diagnoses of current post-traumatic stress disorder [PTSD], depressive disorder, and/or anxiety disorder) that could potentially contribute to memory deficits. Among GW veterans who met the Centers for Disease Control and Prevention criteria for chronic multisymptom illness (N = 272), subjective memory complaint significantly predicted CVLT-II retention scores (β = −0.12, p = 0.04) and marginally predicted CVLT-II delayed recall scores (β = −0.11, p = 0.05) over and above potentially confounding demographic and clinical variables.
Linda R. Abadjian; Iva L. Esparza; Rosemary Reeb
Despite the fact that sleep disturbances are common in veterans with Gulf War Illness (GWI), there has been a paucity of published sleep studies in this veteran population to date. Therefore, the present study examined subjective sleep quality (assessed with the Pittsburgh Sleep Quality Index), insomnia severity (assessed with the Insomnia Severity Index), and risk for obstructive sleep apnea (assessed with the STOP questionnaire) in 98 Gulf War veterans. Veterans with GWI, defined either by the Kansas or Centers for Disease Control and Prevention criteria, had greater risk for obstructive sleep apnea (i.e., higher STOP scores) than veterans without GWI. This difference persisted even after accounting for potentially confounding demographic (e.g., age, gender) and clinical variables. Veterans with GWI, defined by either the Kansas or Centers for Disease Control and Prevention criteria, also had significantly greater insomnia severity and poorer sleep quality than veterans without GWI (p < 0.05), even after accounting for potentially confounding variables. Furthermore, there were significant, positive correlations between insomnia severity, subjective sleep quality, and GWI symptom severity (p ≤ 0.01). In stepwise linear regression models, insomnia severity significantly predicted GWI status over and above demographic and clinical variables. Together these findings provide good rationale for treating sleep disturbances in the management of GWI.
The aim of this study was to examine the relationship between the self-reported frequencies of hearing chemical alarms during deployment and visuospatial function in Gulf War (GW) veterans.