Craig A Stockmeier, Ph.D - US grants

Serotonin axons appear to regulate beta-adrenergic receptor number and function in brain. The objective of this study is to test the hypothesis that serotonin neurons influence noradrenergic neurotransmission in brain by affecting beta-adrenergic receptor number and function, and to determine the nature of the underlying mechanisms that lead to these receptor changes. The specific aims are: 1) to determine the time course of the onset of up-regulation of beta-adrenergic receptors following lesions of serotonin neurons; 2) to determine the specific location of the serotonin lesion necessary to increase beta-adrenergic receptor binding and function (production of cyclic AMP) in brain; 3) to determine whether the administration of a serotonin precursor or receptor agonists will prevent the increase in beta-adrenergic receptor binding and function seen after lesions of serotonin neurons; 4) to determine whether beta-adrenergic receptors are altered by chronic administration of drugs which affect pre- and post-synaptic serotonin function without lesioning serotonin axons; 5) to determine whether the turnover and/or synthesis of norepinephrine is affected by lesions of serotonin neurons and to determine whether changes in these pre-synaptic processes are linked to the up-regulation of central beta-adrenergic receptors seen after specific lesions of serotonin neurons; 6) to determine the pharmacological characteristics and quanyl nucleotide sensitivity of beta-adrenergic receptor binding after up-regulation of the receptor by a lesion of serotonin neurons; and 7) to determine whether serotonin-1 or serotonin-2 receptor binding or function is affected by alteration in noradrenergic neurotransmission. These studies should provide a strong test of the hypothesis that serotonin neurons can directly influence noradrenergic neurotransmission, and should clarify the functional link between two neurotransmitters that have been implicated in mood, sleep, arousal, learning, and neuroendocrine and autonomic nervous system regulation. Since norepinephrine axons are anatomically intact following these lesions of the serotonin system, this model may prove useful in testing and understanding the effects of antidepressant treatments on the regulation of increased numbers of beta-adrenergic receptors in brain.

Disturbances in brain serotonin (5-HT) metabolism have been implicated in the pathogenesis of affective disorders. The objectives of this proposal are to test the hypothesis that suicide victims have increased numbers of serotonin receptors in frontal cortex, and that previous psychiatric history of major depression, violence or impulsive behavior is correlated with receptor binding. The specific aims of this research are: 1) to extend the finding of elevated serotonin 2 (5-HT[2]) receptor binding in homogenates of frontal cortex of violent suicides as compared with nonviolent suicides and matched controls by using in vitro quantitative autoradiography to anatomically localize and quantitate receptor binding. 2. To use in vitro quantitative autoradiography to extend the finding of elevated 5-HT 1A receptor binding in homogenates of frontal cortex of nonviolent suicides as compared with matched controls. 3. To compile a psychological history of the suicide completers used in the receptor binding experiments to determine if previous psychiatric diagnoses are correlated with altered receptor binding. 4. To determine with in vitro quantitative autoradiography whether the high-affinity binding of {3H}paroxetine to the 5-HT transporter complex in sections of frontal cortex of violent and nonviolent suicide completers is different from that in matched controls and if it correlates with 5-HT, and/or 5-HT 1A receptor binding. 5. To study the role of serotonin and dopamine in frontal cortex of suicide completers and matched controls by measuring concentrations of serotonin, dopamine, 5-hydroxyindoleacetic acid, and, homovanillic acid. The studies proposed here to combine psychiatric histories collected from structured interviews with next-of-kin using the SADS-L and SIDP assessment instruments together with quantitative in vitro receptor autoradiography should provide a significant improvement over previous attempts to test the hypothesis that serotonin receptor dysfunction is linked with violence, suicide and/or depression. These studies could provide important preliminary steps toward the eventual goal of imaging monoamine receptors in vivo in patients suffering from depression.

DESCRIPTION (provided by applicant): Plasticity in the hippocampus plays a role in learning and memory, and in neurobiological responses to stress and antidepressant drug action. A significant increase in neuron and glial cell density and a decrease in neuronal soma size has been detected in hippocampus of 19 subjects with major depressive disorder (MDD). The changes in density in MDD were independent of suicide or gender. It is hypothesized that a decrease in hippocampal neuropil, in response to diminished markers of neural growth and synaptic connection, resulting in an increase in neuronal and glial density, is the microscopic basis for the histopathology of the hippocampus in MDD. Aims 1-3 examine the hypothesis that in MDD there is a decrease in hippocampal neuropil, as compared to normal controls. Aims 4-5 examine the hypothesis that there will be diminished markers of neural growth and synaptic connection in the hippocampus in MDD. In Aim 1, stereological experiments in MDD will estimate the total cell number and density of neurons and gila and the corresponding volume throughout the entire hippocampus. In Aim 2, the Golgi silver method will be used to measure spine density, number of dendritic branch points and total length of apical and basal dendritic trees of pyramidal neurons in hippocampal CA1 & CA3 subfields in MDD. In Aim 3, the density and size of glial fibrillary acidic protein (GFAP) -immunoreactive cell bodies, and the areal fraction occupied by GFAP-immunoreactivity in astrocytes will be measured in the hippocampus in MDD. In Aim 4, experiments are designed to stereologically estimate the total immunoreactive cell number and packing density of markers of synaptic plasticity [brain derived neurotrophic factor (BDNF), growth associated protein-43 (GAP-43) and polysialylated-nerve cell adhesion molecule (PSA-NCAM)] throughout the hippocampus in MDD. In Aim 5, experiments will be carried out to quantify mRNA for BDNF and GAP-43 in CA3 and CA4 of the rostral hippocampus in MDD. It is predicted that the hypothesized decrease in expression of BDNF and GAP-43 protein in Aim 4 will be secondary to related decreases in gene expression in the hippocampus. Cellular changes detected in MDD postmortem may underlie hippocampal atrophy detected by some in living subjects with MDD.

[unreadable] DESCRIPTION (provided by applicant): At the request of NIMH (Division of Neuroscience and Basic Behavioral Science, Dr. Douglas Meinecke), this Supplemental application corresponds to Funded Years 03 and 04 of "Hippocampal Atrophy in Major Depression (RO1 MH 67996; PI: C. Stockmeier). The request for Supplemental support to continue and expand tissue collection is an extension of Supplemental Postmortem Brain Collection funding (NOT-MH-01- 010) awarded to Dr. Gregory Ordway as part of RO1 63187 (06/01/02 -11/30/05), and 11 years of NIMH funding for collection to the PI prior to that. Neuroimaging and postmortem brain studies provide evidence for hippocampal pathology in major depressive disorder (MDD). It is hypothesized that a decrease in hippocampal neuropil, in response to diminished markers of neural growth and synaptic connection, resulting in an increase in neuronal and glial density, is the microscopic basis for the histopathology of the hippocampus in MDD. To meet the Specific Aims of the parent RO1 (MH 67996), supplemental funds are requested for the collection of 1) human brain tissue at autopsy and 2) sufficient clinical information from next-of-kin and medical records for retrospective assessment of DSM-IV psychiatric disorders. With informed written consent, brain tissue is sought from subjects suffering a major depressive episode in the last two weeks of life and psychiatrically-normal control subjects matched for age, gender, postmortem interval arid tissue pH. These depressed subjects will not be receiving antidepressant or antipsychotic treatment at the time of death and all subjects must be neurologically and neuropathologically normal. Subjects with MDD must have no current co-morbid Axis I diagnosis of an alcohol or psychoactive substance use disorder. The presence or absence of MDD is determined by consensus diagnosis based on medical records and data gathered from next-of-kin of all subjects with the Structured Clinical Interview for DSM IV Psychiatric Disorders (SCID). At current collection rates, the collection of 6-8 subjects with MDD and about 10 normal control subjects per year for the next two years will permit achievement of the funded specific aims. Current NIH funding to Drs.C. Stockmeier, G. Ordway, G. Rajkowska, R. Duman, B. Karolewicz and M. Austin depends solely on this Supplement for brain tissue to better understanding of the cellular and molecular pathophysiology of the major mental illnesses. [unreadable] [unreadable]

DESCRIPTION (provided by applicant): The Center for Psychiatric Neuroscience (CPN) at The University of Mississippi Medical Center (UMMC), initiated four years ago through a COBRE grant, has developed a multidisciplinary team committed to understanding the etiology of depression. The center now has the potential to develop and sustain an innovative and independently funded research center focused on depression. Faculty in the Center and its academic home, the Department of Psychiatry &Human Behavior, have already reported groundbreaking observations on the roles of neurons, glia, cerebral vasculature, aging, gender, serotonin and glutamate in the etiology of depression. COBRE-supported investigators have increased their competitiveness by attracting extramural funds and publishing in leading journals of neuroscience. The Center will continue to provide an excellent environment for junior and mid-level investigators by working in close collaboration with leading national centers and scientists studying depression to carry out the proposed projects that build on these novel insights into the pathophysiology of depression. To achieve the goal of establishing an innovative and multidisciplinary Center focused on depression, the following Specific Aims are proposed: Aim 1 is to enhance the competitive independent research funding of four investigators, as detailed in research proposals. In addition, leading external and internal scientists in depression will continue to mentor all Center faculty in basic and clinical neuroscience. Aim 2 is to continue the expansion of research resources for the development of innovative depression related projects. Core facilities to accomplish this will include: a) a postmortem human brain collection, b) an animal brain collection focused on behavioral studies related to depression and its treatment, c) imaging facilities for studying quantitative brain biology at the cellular level, and (d) resources for the implementation of molecular biological techniques. Aim 3 is to continue faculty development and growth of new neuroscience investigators through training in cutting-edge technologies and to promote research opportunities in neuroscience for undergraduate and graduate students being mentored by Center faculty. Aim 4 is to sponsor a competitive small grant program that advances research in depression related to the themes outlined in the proposal. The focus on depression, projects examining integrated models, an outstanding Center faculty, training opportunities, a small grant program and generous support by the UMMC administration will ensure the continued growth of a research center that is innovative and multidisciplinary, and moving strongly toward independent funding, and development of a core of senior and new neuroscience faculty.

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Biomedical Research Center infrastructure is inherently complex and is comprised of administrative, mentoring, educational, resource, and research components. The goals of the Administrative Core are (1) to evaluate the effectiveness of center programs and cores, (2) to monitor the progress of individual research subprojects, (3) to administer the small grants program, (4) to ensure that all center programs, core components, initiatives, policies and reporting mechanisms are developed, implemented, and administered within federal granting agency policies and deadlines, (5) to provide fiscal oversight of all subprojects and cores, and (6) to provide high-level program and administrative support to Subproject PIs and Core Directors.

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Despite the benefits of modern brain imaging in living patients and the numerous animal models of psychiatric illness, there will always be a significant need for the analysis of actual brain tissue postmortem. Studies on postmortem tissues can zero in on individual neurons and their helper cells, neuroglia, to assess cellular anatomic features, protein expression and interactions with processes from other individual nerve cells revealing information not attainable from living patients or animal models. The CPN Human Brain Collection Core is directed by Dr. Craig A. Stockmeier, Core Leader. Dr. Stockmeier has extensive experience in the development and management of one of the leading postmortem human brain collections in the country devoted specifically to psychiatric neuroscience.The Human Brain Collection was funded by the National Institute of Mental Health from 1989 through 2007 and is funded by NCRR from 2007 through 2012. The brain collection is run in collaboration with the Departments of Psychiatry and Psychology, Case Western Reserve University, Cleveland, Ohio, and with the Cuyahoga County Coroner Office, Cleveland, Ohio. The psychiatric assessment team includes James C. Overholser, Ph.D. and George J. Jurjus, M.D. Dr. Overholser, a clinical psychologist, has a long-standing career interest in depressive disorders in adolescents and adults. Dr. Jurjus, Director of Inpatient Psychiatry and Detoxification at the Cleveland Wade Park VA Hospital, has been part of the retrospective diagnostic team since 1997 and provides additional expertise in psychoactive substance use disorders. Dr. Stockmeier and his collaborators organize all aspects of the brain collection, including storage of tissue samples and accompanying clinical information. CPN Project Principal Investigators are provided with high-quality postmortem human brain samples meeting inclusion criteria for their research aims involving psychiatric illnesses, as well as the critical supporting information for the brain tissue. Dr. Stockmeier further advises CPN investigators in the selection and matching of appropriate control and psychiatric subjects for their biological studies.

DESCRIPTION (provided by applicant): Depression is the 3rd leading contributor to the global burden of disease; alcohol and illicit drug use are among the top ten contributors to that burden (World Health Organization The Global Burden of Disease: 2004 Update). In ten years of COBRE funding, the Center for Psychiatric Neuroscience (CPN) at The University of Mississippi Medical Center (UMMC) developed cutting-edge core facilities and expanded its focus to the areas of depression and alcohol dependence. Innovative and muitidisciplinary Center investigators have collaborated in ground breaking observations on the roles of neurons and glia, cerebral vasculature, aging, gender, transcription factors, serotonin and glutamate in depression and alcoholism and many have secured independent funding. Our mission in Phase III is to continue building basic research in the pathophysiology of mental illnesses and psychoactive substance use disorders by promoting mentoring, strengthening research cores and, thereby, to increase NIH funding in Mississippi. Specific Aims toward reaching this mission are to: 1) provide support to maintain and expand state-of-the-art research cores that are essential to support basic research across the institution and the state, 2) promote a collaborative and muitidisciplinary mentoring environment that supports innovative pilot research, and 3) develop a self-sustaining center of biomedical research excellence supported by investigator-initiated research grants and collaborative program projects. Our synergistic research cores, available across the institution and state-wide to other COBRE and INBRE investigators, will permit the development of mentored projects along a trajectory of using the Imaging Core and the Molecular and Genomics Core to quantify disease-specific pathology in tissues from the Postmortem Brain Core and modeling such pathology in the Animal Behavior Core to develop phenotypic models of psychopathology and explore novel treatments for depression and psychoactive substance use disorders, including alcohol dependence. State-of-the-art research cores will support mentored basic research in search of new strategies of prevention and treatment for these global challenges to mental health.

DESCRIPTION (provided by applicant): It is well known that ethanol (EtOH) exposure damages brain tissue; however, the underlying mechanisms are not fully understood. Building on our recent work that the newly discovered cell death- mediator, transforming growth factor-¿-inducible early gene 2 (TIEG2) protein, is significantly increased by alcohol in human brain cells and also in adult rat brains, the objective of this innovative proposal is to further characterize the role of TIEG2 in EtOH-induced brain damage. TIEG2 is a transcription factor that inhibits cell growth, induces apoptosis, and increases the expression of monoamine oxidase B (MAO B). The enzymatic activity of MAO B generates H2O2, a major cause of reactive oxygen species (ROS) toxicity. EtOH reportedly increases the activity of MAO B, and secondarily increases the production of H2O2. Our published data show that physiologically-relevant EtOH increases the expression of the TIEG2-MAO B pathway in a neuronal cell line. Over-expression of TIEG2 enhances, whereas inhibitors of MAO B reduce EtOH-induced neuronal death. Additionally, a frequent TIEG2 gene variant (Gln62Arg, a polymorphism of TIEG2) alters the activity of TIEG2 and renders cells more sensitive to oxidative stress than the TIEG2 wild type. Therefore, we hypothesize that ethanol induces the expression of TIEG2 and its variant (the MAO B transcriptional activators). Secondly, we hypothesize that inhibitors of MAO B may provide protection against ethanol-induced brain tissue injury by reducing the TIEG2-MAO B- produced reactive oxygen species (ROS). Our Specific Aims are (1) To identify the molecular signaling components involved in ethanol-induced up-regulation of TIEG2; (2) To determine whether the TIEG2 gene variant (Gln62Arg) sensitizes cells to ethanol toxicity more than the TIEG2 wild type; (3) To determine the protective effects of MAO B inhibitors on cellular survival against ethanol-induced toxicity; and (4) To examine the protective effects of MAO B inhibitors on ethanol-induced neurotoxicity in adult rat brain tissues. The levels of TIEG2, MAO B, and cell death markers will be determined by quantitative real-time RT- PCR, Western blot and TUNEL assays, respectively. The cell proliferation rate, the production of ROS, and the neurodegeneration will also be determined. A comparison will be made among different groups: untreated controls; ethanol-treated; MAO B inhibitor-treated; and ethanol-treated accompanied with MAO B inhibitors. Our proposal will examine the potential role of a novel pathway involving TIEG2 and MAO B in EtOH- induced neurotoxicity and identifies a genetic risk factor that may confer susceptibility to ethanol-induced brain cell damage. It will also serve as the translational study for developing new antioxidant therapeutics for ethanol-induced brain tissue injury. Therefore, this proposal has the potential to greatly impact public health.