Robert Y. Moore - US grants

The principal objective of this research program is to analyze the ultrastructural organization of chemically identified systems of axons in the median eminence of the rat. The proposal consists of three major sections. In the first portion of the proposal, the normal ultrastructural organization of the median eminence will be studied with fine structrual morphometric techniques. Four levels throughout the rostrocaudal axis of the median eminence have been chosen for the analysis on the basis of previous investigations which have demonstrated differential distribution of chemically distinct systems of axons in the median eminence. In the second portion of the program, electron microscopic immunoperoxidase techniques will be utilized to study the organization of individual systems of axons in the median eminence. Antibodies generated against the following antigens are available for these studies: vasopressin, oxytocin, somatostatin, avian pancreatic polypeptide, tyrosine hydroxylase, glutamic acid decarboxylase, luteinizing hormone releasing hormone, serotonin, B-endorphin, adrenocorticotropin releasing hormone, Alpha-melanocyte stimulating hormone, leu-enkephalin and neurotensin. In the final phase of the investigation, attempts will be made to perfect techniques which will allow localization of two or more antigens within a single ultrathin section in order that the interrelation of dense and overlapping, although chemically distinct, systems of axons can be studied.

Cyclic, or rhythmic, events are ubiquitous in nature. In recent years it has become evident that one class of biological rhythms with a periodicity approximating a day, circadian rhythms, represent a major factor in the organization of an animal's internal milieu to provide maximal adaptation with its environment. The purpose of this research program is to identify and analyze the central neural mechanisms which are responsible for the production of circadian rhythms in mammals. Previous work has been dedicated to problems of localization of function. This work has identified the retinohypothalamic projection to the suprachiasmatic nucleus of the hypothalamus and shown it mediates entrainment of circadian rhythms. Ablation of the suprachiasmatic nucleus appears to abolish circadian rhythms suggesting that the nucleus is an important component of central circadian oscillating mechanisms. The proposed work will further analyze this by studying the effects of a variety of lesions on entrainment and maintenance of circadian rhythms. These will be performed in developing and adult animals. Further studies will examine the ontogeny of circadian rhythmicity in the nucleus, the morphological development of the nucleus in vivo and in vitro, and the detailed organization of the nucleus and its afferent and efferent projections. The goal is to determine if the suprachiasmatic nucleus is a central circadian oscillating system in the mammalian brain and to characterize, as completely as possible, the organization and properties of such a system which serves a unique and important function in the mammalian nervous system.

body temperature regulation; circadian rhythms; animal old age; aging; laboratory rat;

Circadian rhythms are fundamental components of animals' adaptation to their environment. They provide a precise temporal organization of physiological and behavioral processes that is essential to survival. In mammals, circadian rhythms are generated by a circadian timing system (CTS) which contains a pacemaker, the suprachiasmatic nucleus of the hypothalamus (SCN) with its efferent projections and two visual entraining pathways, the retinohypothalamic tract (RHT) and the geniculohypothalamic tract (GHT). Disorders of the CTS are observed in sleep disorders, affective disorders, neuroendocrine diseases and ageing. The proposed research will analyze the functional organization of each component of the CTS. This will include a detailed analysis of retinal ganglion cells projecting to the SCN, and the source of the GHT, the intergeniculate leaflet (IGL). The IGL will be characterized morphologically and its afferent and efferent connections will be determined. we will attempt to determine the transmitters utilized by the RHT and GHT. The function of the GHT will be analyzed by measuring neuropeptide Y and enkephalin content and message level in the IGL, and SCN where appropriate, at different times of the circadian day. The function of entraining pathways will be analyzed by determining the phase the firing rate rhythm from single unit recordings from SCN in response to pharmacological treatments. The organization efferent projections of the SCN, particularly to the retrochiasmatic and subparaventricular areas, will be analyzed using retrograde transport, anterograde transport and immunocytochemistry. The functional relations between the CTS and effector systems expressing circadian function will be studied using transplants of fetal hypothalamic tissue. The objective is to determine what components of the SCN are required to restore function, what connections between host and graft are required and whether there is any specificity between graft content, location or connections and the type of circadian function that is restored.

The Alzheimer's Disease Research Center (ADRC) at the University of Pittsburgh was established in 1985 as a mechanism for integrating, coordinating and supporting new and ongoing research in Alzheimer's disease (AD) and aging. The present proposal is a request for a 5 year renewal of the ADRC. The goal of the ADRC for the next 5 years is to provide core support for investigators and has three principle objectives. The first objective is to support and foster research into the cellular and molecular neurobiology of AD with specific reference to understanding the cellular, metabolic and molecular changes that could mediate the pathological, physiological and clinical abnormalities. This goal will be approached with studies which will investigate: A) membrane metabolic and molecular dynamics in AD and control erythrocytes (Project #2, Pettegrew) as compared to clinical symptomatology and in vivo 31P NMR findings in brain (NIA- funded, Pettegrew); B) the structural and functional comparison of beta- amyloid and epidermal growth factor peptides (Pilot Project #1, Klunk); C) excitatory amino acid transmitters and receptors in pyramidal cells and the relationship of this system to the pathology and symptomatology of AD (Project #4); D) tyrosine hydroxylase-immunoreactive neocortical neurons and their role in AD, Parkinson's and diffuse Lewy body disease (Project #5, Lewis); and E) possible pharmacokinetic mechanisms to explain the high incidence of adverse drug reactions in AD (Pilot Project #4, Perel). The second objective is to support and foster research directed at understanding the clinical syndrome of AD with specific reference to functional dissociations. This goal will be approached with studies which will investigate: A) measures of cognitive slowing in patients who present with mixed symptoms of depression and dementia (Project #1, Nebes); B) SPECT imaging of frontal and temporal cortex as a predictor of short versus long-term memory loss (Pilot Project #5, Becker); C) the effect of sleep apnea on cognitive, affective and behavioral functioning in AD (Pilot Project #3, Hoch); D) computer simulation of characteristics of dementia as compared to depression (Pilot Project #8, Webster); and E) the merits of a didactic, interactive, educational approach to educate and induce changes in caregiver knowledge, attitudes and behavior. The third goal is to support and foster mechanisms for the delivery of information generated by the Center to all ADRC investigators and to clinicians and investigators outside the University setting.

The primary aim of the Center for Functional Brain Imaging at the University of Pittsburgh Medical Center is to substantially expand existing clinical and basic research programs in mental disorders by the judicious introduction of PET functional brain imaging. This Center will provide the infrastructure for the initiation of a diverse group of new research projects using PET to study mental disorders. These projects include: correlation of magnetic resonance spectroscopy abnormalities to regional changes in glucose metabolism and blood flow in aged, demented, schizophrenic and autistic patient groups; measuring regional brain function after serotonergic pharmacological challenges in obsessive-compulsive and suicidal patients; development of new cognitive tasks for specific activation of frontal lobe regions; studying metabolic changes after sleep deprivation in normal aged and depressed populations; combining event-related potential data with regional activation seen by PET to elucidate the basis for shifting attention; measuring D2 receptor occupancy in cortical structures during controlled neuroleptic therapy of schizophrenics; correlation of focal mesial-temporal metabolic defects to clinical courses of demented patients; determination of frontal lobe dysfunction in young patients with anti-social personalities; and examining the metabolic consequences of sub-cortical white matter MRI hyperintensity lesions in elderly depressives. This group of proposals all arise from investigators in funded psychiatry and psychology research groups who bring considerable expertise to each project and carefully characterized patient populations. The inclusion in the Neurocognitive Core of key investigators in the Department of Psychology at Carnegie Mellon University and the development of collaborative projects further enriches the Center and the proposed research. We believe that the integration of novel, experimental and clinical paradigms with straightforward, established PET techniques is the most logical approach for achieving the initial aims of this Center. The availability of new receptor ligand tracers through the radiochemistry group will create the basis for the next phase of clinical imaging research in the Center.

Synucleinopathies are now recognized as major causes of dementia. The principal synucleinopathies are the overlapping clinical entities of Parkinson disease (PD), including Parkinson disease with dementia (PDD), and dementia with Lewy bodies (DLB). PDD and DLB are the most common causes of dementia after Alzheimer disease (AD). A clinical distinction between PDD and DLB, and distinguishing them from AD, is often difficult and, perhaps more importantly, the clinician encounters many situations in which it is unclear from clinical data and structural imaging whether a dementia reflects predominantly a single process or a complex one with Alzheimer changes coexisting with one or more of the other pathologies. In addition, as more specific therapies become available, it will be important to have methods to distinguish among the contributing pathological processes. The intent of this project is to use amyloid PET (PIB PET) combined with Clinical and neuropsychological evaluation, fluorodeoxyglucose (FDG) PET and dopamine transporter PET (in DLB ) to determine the contribution of amyloid deposition to dementia in PD and DLB. The specific aims are as follows: 1) to perform PIB PET in DLB and PDD subjects that have been carefully characterized with respect to clinical features, changes on structural MRI, PD rating scales, neuropsychological performance, FDG PET and DAT PET (DLB); 2) to perform PIB PET at study entry and after 3 years in PD subjects characterized at both time points with respect to clinical features, PD rating scales, changes on structural MRI, neuropsychological performance and FDG PET. The overall objectives of the project are to determine the following: 1) the contribution of beta-amyloid accumulation to the dementia in PDD and DLB; 2) the role of beta-amyloid accumulation in the conversion of PD to PDD; 3) the contribution of FDG, PIB PET and dopamine transporter PET, correlated with clinical evaluation, neuropsychological testing and structural imaging, to understanding the pathophysiology of dementia associated with synucleinopathies.