center for molecular and behavioral neuroscience contributing faculty and research
In addition to the investigation shown here, read about clinical trials now in progress at the Center.
Uma Rao, M.D.
Dr. Uma Rao is Professor of Psychiatry at Meharry Medical College and Vanderbilt University in Nashville, Tennessee. She serves as the Director of Molecular and Behavioral Neuroscience and holds the Endowed Chair in Brain and Behavior Research at Meharry Medical College. She is the Senior Research Scientist in the Meharry Clinical and Translational Research Center (MeTRC) and the Research Centers for Minority Institutions (RCMI) Program in Women's Health at Meharry Medical College. She also serves as the Program Director for the Methamphetamine Research Program at Meharry Medical College.
Dr. Rao has been involved in child and adolescent mood and substance use disorders research for more than 20 years, and her primary areas of interest are adolescent depression and addictive disorders during the developmental transition to adult life. Three themes emerge from this research: (1) longitudinal clinical course of early-onset depression and addictive disorders, and impact of these disorders on adult emotional and social adjustment; (2) predictors of differential longitudinal clinical course, including clinical, neurobiological and psychosocial processes; and (3) developmental and ethnic influences on neurobiological processes associated with mood and substance use disorders. In addition to the above-described studies on risk factors and pathophysiology of mood and substance use disorders, Dr. Rao is involved in intervention research. The long-term goals of Dr. Rao's research program are to develop and test more specific and effective preventive and treatment interventions for adolescent depression in addition to developing preventive strategies for substance use disorders in depressed and non-depressed youth.
Dr. Rao has received research funding from the National Institute on Drug Abuse, the National Institute of Mental Health, the National Institute on Minority Health and Health Disparities and the National Center for Research Resources.
Current Research Projects:
Treatment Prediction in Adolescent and Adult Depression
Researcher: Uma Rao, M.D.
Funding Source: National Institute of Mental Health (NIMH)
Project Summary: Although there is growing evidence for continuities in adolescent and adult depression, with similarities in clinical presentation and natural history, maturational differences also have been highlighted. Specifically, several studies reported greater variations in electroencephalographic (EEG) sleep changes, hypothalamic- pituitary-adrenal (HPA) activity and antidepressant (AD) response in depressed adolescents compared with the findings in adults. This proposal aims to understand the mechanism(s) underlying these developmental differences and to develop a strategy for use in identifying those patients, both youngsters and adults, who might benefit from AD treatment in general, and from bupropion treatment in particular. Based on the results of preliminary studies conducted in our laboratory, this investigation proposes to predict AD response to sustained-release bupropion in depressed adolescents and adults by assessing rapid eye movement (REM) sleep and HPA activity responses to single-dose bupropion administration prior to initiating treatment.
Coping with Interpersonal Violence in African American Women
Researcher: Uma Rao, M.D.
Project Summary:Using a prospective design, the study examines the trajactories of hypothalamic-pituitary-adrenal activity, sympathetic nervous system activity and posttraumatic stress disorder symptoms in young African-American women who recently experienced an episode of interpersonal violence. Non-Hispanic White women serve as the control group.
Ethnicity, Gender, and Pediatric Pain
Researcher: Uma Rao, M.D.
Project Summary: The goal of this study is to assess biological, psychological, and social-contextual factors associated with pain experiences in African-American and Non-Hispanic White boys and girls.
Biopsychosocial Models of Risk for PTSD
Researcher: Matthew Morris, Ph.D.
Funding Source: National Institute of Child Health/Human Dev. (NICHD)
Project Summary: This project seeks to identify cognitive and neurobiological markers of risk for posttraumatic stress disorder (PTSD) and/or major depressive disorder (MDD) in the acute aftermath of trauma. The study will investigate longitudinal pathways leading from interpersonal violence (IPV) exposure to PTSD and/or MDD in a sample of 60 women recently exposed to IPV and 40 non-exposed women using four waves of data collection (within one month after exposure to IPV, and at one, three, and six months following the initial assessment). Although women are twice as likely as men to develop PTSD and/or MDD after exposure to trauma, the mechanisms underlying this increased risk remain unclear. Identifying individuals at elevated risk for these disorders is critical for developing effective early intervention programs.
Twum Ansah, Ph.D.
Department of Neuroscience and Pharmacology
The research in Dr. Twum Ansah's laboratory seeks to understand the neurobiological mechanisms that mediate neurological disorders, such as Parkinson's Disease as well as psychiatric disorders such as depression and drug abuse, all of which involve the dopaminergic system and its regulation by other systems, such as the serotonergic system. His major research efforts are being devoted to systematically investigate alterations in the serotonergic system and to understand its role in the hypokinesia produced by lesioning of the dopaminergic system with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). The objective is to understand the role of serotonin in the neurobiology of Parkinson's Disease and how manipulating the serotonergic system might alter the course of the disease, as a prelude to identification of novel therapeutic targets for the disease.
Clivel George Charlton, Ph.D.
Professor and Chairman
Department of Neurobiology and Neurotoxicology
Dr. Charlton's laboratory is exploring the possible causal relationship between excess methylation in the brain and Parkinson's disease. Methylation depletes the amount of the essential neurotransmitter dopamine and increases levels of lyso-phosphatidyl choline, which disrupts the structure of biological membranes in the microcompartment where this occurs. Dr. Charlton and his colleagues have observed that injection of the methyl donor, S-adenosyl-methionine (SAM), into the brain of rodents results in extensive brain methylation and causes transient tremor, hypokinesia, rigidity, and abnormal posture, changes that resemble the motor deterioration that accompanies Parkinson's. Consistent with their hypothesis of a role of methylation in the pathway leading to Parkinson's disease is the finding that MPP+, a toxic metabolite linked to Parkinson's disease development in human beings, increases SAM-dependent methylation in the brain. The laboratory is exploring possible therapeutic interventions to alter these methylation processes. Interestingly, a current Parkinson's therapy, L-dopa, diminishes the Parkinson's-like symptoms in SAM-injected rats. However, there are considerable side effects and loss of effects of L-dopa when given therapeutically. Dr. Charlton and his colleagues are also exploring the molecular basis for these unwanted treatment sequelae.
Sukhbir Mokha, Ph.D.
Professor, Meharry Department of Neuroscience and Pharmacology
Adjunct Professor of Pharmacology, Vanderbilt University
Director of Graduate Studies, Neuroscience Program
Dr. Mokha's laboratory is investigating the neurobiology of pain and analgesia in normal and pathological states using electrophysiological, behavioral, cellular, and molecular techniques. Many painful syndromes/disorders such as migraine, trigeminal neuralgia, temporomandibular joint disorder (TMJ/TMD), and irritable bowel syndrome (IBS) are more prevalent in women than in men. Dr. Mokha and his colleagues are interested in understanding the biological mechanisms that generate the higher prevalence of painful syndromes in women. Specifically, the laboratory is investigating whether activation of endogenous noradrenergic or serotonergic pathways involving G protein–coupled receptors (opioid, noradrenergic, and serotonergic) produce estrogen-dependent, sex-specific inhibition of pain mechanisms , in both spinal and trigeminal systems. Estrogen-dependent decreased inhibition in the female could contribute to the higher prevalence of painful syndromes in women. They have already provided evidence that estrogen decreases the analgesic effects produced by activation of α₂-adrenoceptors and opiod or opiod-like receptors (ORL1) in the spinal cord and trigeminal system and have shown that estrogen alters the expression of the gene encoding ORL1.
Mitchell Parks, M.D.
Assistant Professor, Department of Psychiatry & Behavioral Sciences
Dr. Parks's research examines the nexus of two health disparities in African-American women: their documented increased incidence of alcohol use disorders and their prevalence of HIV infection. The technique employed to address the question of why these two disparities occur in this population is functional magnetic resonance imaging (fMRI). fMRI utilizes hemoglobin as a natural tracer to differentially determine activity in brain areas. Dr. Parks's previous work with chronic alcoholic patients determined their different utilization of frontal and parietal regions in response to simple motor tasks. The objective in the work with African-American women is to use fMRI to determine whether routine or binge ingestion of alcohol incurs changes in brain physiology that might lead to HIV infection risk.