Daniel Peter Perl, MD, Columbia University - US grants

Senile dementia, Alzheimer's type (SDAT) is one of the most common, yet most poorly understood of neurologic disorders. The principle neuropathologic lesion encountered in the brains of patients with SDAT is theneurofibrillary tangle (NFT). Recent studies have pointed to the possible role of excess aluminum in the pathogenesis of SDAT. Using scanning electron microscopy in conjunction with electron probe analysis, we have developed techniques for the determination of intraneuronal trace element analysis. Using these techniques we have identified intraneuronal accumulations of aluminum within neurofibrillary tangle-bearing cells in the hippocampus and frontal cortex of patients with SDAT. With this as a basis, we have begun to study the intraneuronal trace element composition of brain specimens derived from the Chamorros of Guam. The Chamorros are a people characterized by a striking propensity to extensive NFT formation. This tendency among the Chamorros is also accompanied by an exceedingly high incidence of ALS and Parkinsonism with severe dementia (PD). Preliminary data indicate that tangle-bearing hippocampal neurons in these cases also demonstrate significant aluminum accumulations. Epidemiologic evidence suggests that these intracellular accumulations are associated with local environmental factors on Guam related to water and soil conditions. We intend to collect a series of brain tissue samples of Guananian ALS and PD cases and non-impaired controls, as well as a comparable series of ALS, idiopathic Parkinsonism and SDAT cases and normal controls from the mainland U.S. Intracellular trace element analysis will be performed on neurons within the hippocampus, cortex, and the motor and extraphyramidal systems. Sensitive quantitative measures of tissue levels of several trace elements also will be obtained by atomic absorption spectrometry. These data will provide a means to evaluate the possible role of neurotoxic trace element accumulations in NFT formation, motor neuron and extrapyramidal system degeneration. By analysis of the clinical, metabolic and epidemiologic data avaiable from these cases, we will evaluate potential sources for these element abnormalities.

Senile dementia, Alzheimer's type (SDAT) is one of the most common, yet most poorly understood of neurologic disorders. The principle neuropathologic lesion encountered in the brains of patients with SDAT is theneurofibrillary tangle (NFT). Recent studies have pointed to the possible role of excess aluminum in the pathogenesis of SDAT. Using scanning electron microscopy in conjunction with electron probe analysis, we have developed techniques for the determination of intraneuronal trace element analysis. Using these techniques we have identified intraneuronal accumulations of aluminum within neurofibrillary tangle-bearing cells in the hippocampus and frontal cortex of patients with SDAT. With this as a basis, we have begun to study the intraneuronal trace element composition of brain specimens derived from the Chamorros of Guam. The Chamorros are a people characterized by a striking propensity to extensive NFT formation. This tendency among the Chamorros is also accompanied by an exceedingly high incidence of ALS and Parkinsonism with severe dementia (PD). Preliminary data indicate that tangle-bearing hippocampal neurons in these cases also demonstrate significant aluminum accumulations. Epidemiologic evidence suggests that these intracellular accumulations are associated with local environmental factors on Guam related to water and soil conditions. We intend to collect a series of brain tissue samples of Guananian ALS and PD cases and non-impaired controls, as well as a comparable series of ALS, idiopathic Parkinsonism and SDAT cases and normal controls from the mainland U.S. Intracellular trace element analysis will be performed on neurons within the hippocampus, cortex, and the motor and extraphyramidal systems. Sensitive quantitative measures of tissue levels of several trace elements also will be obtained by atomic absorption spectrometry. These data will provide a means to evaluate the possible role of neurotoxic trace element accumulations in NFT formation, motor neuron and extrapyramidal system degeneration. By analysis of the clinical, metabolic and epidemiologic data avaiable from these cases, we will evaluate potential sources for these element abnormalities.

This Pilot Project will initiate studies on brain specimens of elderly psychiatric patients who 40+ years ago underwent frontal lobotomy. In conjunction with an ongoing Program to study biologic issues related to schizophrenia we are actively collecting brain specimens derived from patients in a large psychiatric hospital. In this hospital we have identified a large cohort of post-lobotomy patients who are sufficiently old to be at high risk of dying and being autopsied in conjunction with the schizophrenia Program. The lobotomy procedure leaves the rostral prefrontal cortex intact while mechanically severing its efferent and afferent connections to the rest of the brain. The proposed pilot project will examine aspects of the connectivity hypothesis of Alzheimer's disease. This hypothesis suggests that the distribution of the lesions associated with Alzheimer's disease follows consistent patterns which coincide with certain neuroanatomic pathways with selective involvement of neurons having long corticocortical projection pathways. Furthermore, the connectivity hypothesis proposes that the progressive sequence of involvement of brain structures by the lesions of Alzheimer's disease is governed by their neuroanatomic connections. The availability of this unique source of elderly post-lobotomy brain specimens will allow us to investigate whether the rostral prefrontal cortex, effectively deafferented from the remainder of the brain, will develop neuropathologic lesions associated with Alzheimer's disease of long corticocortical neuronal connections for over 40 years. We will specifically investigate the extent and distribution of neurofibrillary tangles, senile plaques and dystrophic neurites in the rostral prefrontal cortex as compared to the involvement in neocortical regions with remaining connections and in non-operated schizophrenia subjects with a comparable degree of neocortical senile changes. This pilot project will allow us to begin to test whether long corticocortical connections re required for the formation of these important features of Alzheimer's disease and thus test crucial aspects of the connectivity hypothesis. Preliminary data are presented to indicate that we have already collected some brain specimens which are appropriate for this study. In these specimens senile plaques, surrounded by dystrophic neurites, do appear in the deafferented prefrontal cortex while neurofibrillary tangles are rare. The results of this pilot project will be used to apply for further support of a more detailed study of these important issues in these unique brain specimens.

Although much is known about the biochemical and morphologic substrates of the late stages of AD, relatively little is currently understood of the initial phases of this disorder and how those initial phases differ from what has been referred to as "normal aging". Based on our review of the literature, it is clear that prospective, longitudinal cognitive assessment is imperative for the identification of intact intellectual functioning as well as the earliest aspects of cognitive decline leading eventually to clinically apparent AD. Addressing these deficiencies in our knowledge, this project will perform detailed neuropathologic evaluations in order to characterize the extent and distribution of lesions in individuals judged, based on serial prospective cognitive assessment, to have either a) intact and stable cognitive functioning, b) early mild cognitive decline but with impairment insufficient to meet NINCDS Alzheimer's disease criteria or c) recent onset (early) Alzheimer's disease. Through the collection and morphologic examination of elderly subjects initially identified with intact cognitive function we anticipate having available to us significant numbers of brain specimens which will represent clinically verified normal controls of advanced age as well as individuals who appear to be in the earliest phases of AD. Our objective is to determine the pattern of the development of the cardinal lesions associated with the earliest phases of Alzheimer's disease. In our studies we will assess the extent and distribution of neurofibrillary tangles and senile plaques in the entorhinal cortex, hippocampus and selected neocortical regions of such cases. We will also investigate synaptic integrity through the use of anti-synaptophysin immunoreactivity as a potential correlate of early cognitive loss. Finally, using an antibody to vascular heparan sulphate proteoglycan we will explore evidence of alterations of the cerebral cortical microvasculature in these cases. We will cognitive impairment and to distinguish the regional pattern of these alterations. This project represents an unprecedented opportunity to explore issues of the neuropathologic substrates of normal aging and early phases of AD in an extremely elderly population.

The specific aims of the Brain Bank Core are to obtain, characterize, describe, dissect, preserve and distribute to different researchers engaged in Alzheimer's disease research, brain tissues obtained from normal control, and Alzheimer's disease subjects. The Brain Bank Core will obtain and bank brain tissues from as many of the subjects enrolled by the Recruitment and Diagnosis Core and studied by the Neurophyschology project as possible. The Brain Bank Core will perform autopsies with the lease possible post-mortem delay, and will maintain permanently all pertinent specimen related information in a manner accessible to all past, present and future investigators using the Brain Bank. The acquisition and banking of the projected cohorts will provide a unique resource to only for the proposed studies, but for generations of studies and investigators to come. The brain banking procedures outlined in this application have been designed to preserved the tissues optimally for as broad a set of experimental methodologies as possible. After extraction, brain specimens will be photographed, weighted and any gross lesions and abnormalities note. The right half of the brain will be preserved in paraformaldehyde for neuropathological and neuroanatomical studies. The left half will be dissected in 0.5-0.8 cm coronal slabs, and after identification of the structures in each slab they will be snap frozen in liquid freon. Frozen slabs will be kept at -80C until sub-dissected for use by specific studies. The Brain Bank Core will serve all five projects proposed in this application either directly or indirectly. The Brain Bank Core will contribute to the Neuropsychology, Family History and Acute Phase Reactants projects (Projects 1, 2 and 4) by performing autopsies of subjects who have been studied in life. The neuropathological information obtained (Project 5) on these cases will enhance the Neuropsychology project by providing data on the neuropathological of cognitive decline in the aged. The Neurochemistry project (Project 3) will use the tissues banked by this core to investigate the neurochemical correlates of cognitive decline in the aged. The procedures used by the Brain Bank Core have been optimized to enhance and facilitate multiple neurochemical studies of each case banked. In addition the acquisition and banking of brain tissues from this unique cohort of subjects will augment the utility of the Brain Bank for projects funded by other grants (eg., ADRC, Cellular and Molecular Markers in Schizophrenia-PPG), by providing specimens from normal elderly controls whose cognitive status has been confirmed by rigorous ante- mortem testing.

DESCRIPTION (provided by applicant): Over the years, neuropathologic characterization of autopsy-derived brain tissues has occupied a central position in research on amyotrophic lateral sclerosis-parkinsonism dementia complex of Guam. Within this Program, the Neuropathology-Brain Bank core (core C) will continue to receive brain specimens (both fixed and frozen) from the Clinical core (core B) on Guam. These brain specimens will be derived from three sources, a) cases showing clinical evidence of age-related neurodegeneration who have been identified and followed by the Clinical core, b) deceased members of a large cohort of elderly Chamorros (age 65 or above) who have been identified and longitudinally assessed for neurologic and cognitive function (see subproject by Galasko) and c) specimens that were obtained in conjunction with prior research studies on Guam in order to construct a brain tissue repository that is more fully representative of all forms of neurodegenerative disease on Guam as well as include additional examples of specimens derived from patient who died in the earlier phases of the disease outbreak. The core will 1) provide supervision and advice to the Clinical core (core B) to enable the Program to obtain optimally fixed and preserved autopsy-derived brain specimens with a minimum amount of postmortem delay 2) carry out MRI examinations on all fixed brain specimens, 3) perform dissection, preservation and storage of received brain specimens and distribute appropriate tissue samples to investigators within the Program, 4) perform complete neuropathologic evaluation and diagnosis of each brain specimen, 5) determine the extent and distribution of relevant neuropathologic lesions in these specimens, 6) incorporate these data above in the neuropathology database, 7) obtain Guam-derived brain specimens obtained in conjunction with prior NINCDS registry studies that were evaluated neuropathologically and are being stored in the Brain Research Institute, Niigata, Japan, and 8) retain in a preserved state brain samples obtained in conjunction with the above and serve as a national/international brain bank repository to make available appropriate brain tissue specimens to qualified researchers.

The Neuropathology Core will continue to play a vital role in the ongoing Program. The Neuropathology Core serves to obtain autopsy-derived brain specimens from individuals who have been evaluated and followed longitudinally by the Clinical Core especially residents of the Jewish Home and Hospital for the Aged, a very large academically affiliated nursing home. We strive to obtain the brain specimens with the shortest post-mortem interval and for the entire specimen collection the mean postmortem interval is less than 6 hours. The specimens are dissected and preserved in a manner that maximizes their utility for the needs of both the proposed experiments within the Program as well as other research projects within the Mount Sinai ADRC as well as independent aging-related projects. This includes snap freezing one half of the brain specimen and fixing the other half is freshly prepared paraformaldehyde. The dissection protocol in place allows for the preparation of selected regions of the brain in such a way that the non-biased sampling techniques of stereology can be applied to quantify lesion and neuron numbers. A detailed neuropathologic workup is carried out to establish a neuropathologic diagnosis as well as to document the extent and distribution of relevant neuropathologic lesions. These data are entered into an extensive data base which can be integrated into the clinical data base for the purpose cliniconeuropathologic correlative investigations. The Neuropathology Core will also provide assistance and expertise in the morphologic evaluation of newly developed transgenic animals as well as those transgenic animals exposed to experimental manipulations. We will interpret the nature of any identified lesions for their relevance as models of AD or other human neurodegenerative conditions. Because this Brain Bank has been operating for approximately 18 years, an efficient and effective operating structure for the Brain Bank already exists. The tissues we have collected have been extensively used in a wide range of studies. They are extensively requested both by researchers within the ADRC, the greater Mount Sinai research community and by many other investigators throughout the US and even internationally. The overall aim of this core is to continue to maintain and operate the Brain Bank in such a way as to meet the needs of the cores and studies in the ADRC in an optimal fashion.

The Neuropathology Core will continue to play a vital role to the Mount Sinai ADRC. The Neuropathology Core serves to obtain autopsy-derived brain specimens from individuals who have been evaluated and followed longitudinally by the Clinical Core especially residents of the Jewish Home and Hospital for the Aged, a very large academically affiliated nursing home. We strive to obtain the brain specimens with the shortest post-mortem interval and for the entire specimen collection the mean postmortem interval is less than 6 hours. The specimens are dissected and preserved in a manner that maximizes their utility for the needs of both the proposed experiments within the Center as well as other AD and aging-related research projects. This includes snap freezing dissected portions of one half of the brain specimen and fixing the other half is freshly prepared paraformaldehyde. The dissection protocol in place allows for the preparation of selected regions of the brain in such a way that the non-biased sampling techniques of stereology can be applied to quantify lesion and neuron numbers. A detailed neuropathologic workup is carried out to establish a neuropathologic diagnosis as well as to document the extent and distribution of relevant neuropathologic lesions. These data are entered into an extensive data base which can be integrated into the clinical data base for the purpose cliniconeuropathologic correlative investigations. Because this Brain Bank has been operating for approximately 18 years, an efficient and effective operating structure for the Brain Bank already exists. The tissues we have collected have been extensively used in a wide range of studies. They are extensively requested both by researchers within the ADRC, the greater Mount Sinai research community and by many other investigators throughout the US and even internationally. The overall aim of this core is to continue to maintain and operate the Brain Bank in such a way as to meet the needs of the cores and studies in the ADRC in an optimal fashion as well as the research community both at Mount Sinai and elsewhere.

The Neuropathology Core has been in operation since 1985 and continues to play a vital role to the Mount Sinai ADRC. The Neuropathology Core serves to obtain autopsy-derived brain specimens from individuals who have been evaluated and followed longitudinally by the Clinical Core. We strive to obtain brain specimens with a short post-mortem interval and for the entire specimen collection the median postmortem interval is less than 6 hours. The specimens are dissected and preserved in a manner that maximizes their utility for the needs of both the proposed studies within the Center as well as other AD and aging-related research projects that we actively contribute to. Our procedure includes snap freezing dissected portions derived from one half of the brain specimen and fixing the other half in freshly prepared paraformaldehyde. The dissection protocol in place allows for the preparation of selected regions of the brain in such a way that the non-biased sampling techniques of stereology can be applied to quantify normal and pathologic features. A detailed neuropathologic workup is carried out to establish a neuropathologic diagnosis as well as to document the extent and distribution of relevant neuropathologic lesions. These data are entered into an extensive data base which can be integrated with the clinical data base in order to explore cliniconeuropathologic relationships. Because this Brain Bank has been continuously operating for approximately 24 years, an efficient and effective operating structure for the Brain Bank already exists. The tissues we have collected have been extensively used in a wide range of studies. They are requested by numerous researchers within the ADRC, the greater Mount Sinai research community and by many other investigators throughout the US and even internationally. The overall aim of this core is to continue to maintain and operate the Brain Bank in such a way as to provide state-of-the-art diagnoses, quantify the extent and distribution of relavent neuropathologic lesion, and satisfy the needs of the cores and projects in the ADRC as well as current and future requirements of the research community both at Mount Sinai and elsewhere.