Gary W. Arendash - US grants

Although brain tissue transplantation in rats has recently been used to investigate the development and potential for functional integration of transplanted brain regions, exploring reproductively-important brain processes with this new research tool has not yet been cohesively addressed. In this regard, little is known about the exact mechanism(s) by which gonadal hormones (such as testosterone) organize or alter the development of the mammalian brain to bring about its sexual and neuroanatomical differentiation. Therefore, the studies of this proposal's first section will attempt to elucidate the mechanism(s) of steroid action on the brain by investigating the effects of testosterone on the development of immature, male brain tissue after its transplantation into the brain of recipient female neonates. Particular emphasis will be given to possible gonadal steroid effects on the survival of transplanted neurons, their neuroanatomical structure, and their potential for migration. As a challenge for brain tissue transplants to alter the neural functions of recipient animals, the studies of this proposal's second section will test the ability of transplanted male brain tissue to establish functional connectivity with the host female brains, as evidenced by transplant-induced alterations in the recipient animals' sexual behavior and Luteinizing Hormone secretory patterns. If such modifications in brain functions are observed, strong evidence will have been provided not only for the functional integration of transplanted tissue, but for the feasibility of using brain tissue transplants clinically to restore normal function to damaged or diseased brain areas. The studies of this proposal involve a new intraparenchymal transplantation technique designed to discretely place transplanted brain tissue intothe most natural environment for its normal development and establishment of functional connectivity. As such, this proposal represents the first full-scale attempt to investigate the development and function of brain reproductive mechanisms through the use of brain tissue transplantation.

Although retrospective studies suggest that a lifelong pattern of high mental activity is protective against Alzheimer's Disease (AD), prospective longitudinal studies have not been done. As well, the contribution of social and/or physical activity to AD risk-reduction has not been adequately evaluated in controlled clinical studies nor has the potential benefit of long-term, intensive cognitive rehabilitation in AD patients. The availability of AD transgenic mice make it possible to investigate these issues in fully-controlled longitudinal studies. Our preliminary studies indicate that "complete" environmental enrichment (e.g., cognitive, social, and physical activity) is both protective and therapeutic against cognitive impairment in AD transgenic mice ? this, without affecting brain beta-amyloid deposition. The present project will first elucidate the role of each contributing component (e.g., cognitive,social, and physical) to the protective ability of complete environmental enrichment; this isolation of enrichment's contributing components is impossible to achieve in clinical studies. Second, this project will evaluate the potential of both continous and session-restricted environmental enrichment as a treatment to cognitively-impaired AD transgenic mice. All cognitive rehabilitative therapeutic in AD patients are session-restricted, so it is important to investigate this protocol in AD transgenic models. Third, a variety of brain neuropathologic and neurochemical processes will be assessed that could be mechanistically involved in the cognitive benefits provided by environmental enrichment or it's various component activities. These processes include neurogenesis, neurodegeneration, oxidative stress, neuroinflammation, and growth factor modulation. Collectively, the studies of this project are of substantial public health significance because they investigate the potential for "modifiable" factors (cognitive, social, physical activity) to protective against or treat AD, as well as provide important insight into likely cellular/molecular mechanisms that may be involved therein.

It is expected that a number of researchers in the ADRC will be involved with, or wish to become involved with, behavioral and/or histopathologic studies in genetically-manipulated mouse models for AD. The Mouse Behavior and Neuropathology (MBN) core is the central core through which such studies will be designed and performed at the ADRC, utilizing equipment and expertise of the MBN Core. Thus, the main function of the MBN Core will be to acquaint other Pi's and their laboratory personnel with the collection and analysis of behavioral/histopathologic data, as well as provide expertise in the interpretation of results obtained. Specifically, the MBN Core will 1) design and carry out behavioral/histopathologic studies in geneticallymanipulated mouse models of AD that involve MBN Core personnel 2) assist other ADRC researchers in designing and carrying out mouse behavioral/histopathologic studies that relate to the research questions they are addressing 3) provide training and consultation in behavioral and histopathologic methodologies to ADRC researchers, and those utilizing ADRC resources, so that they may incorporate such methodologies into their research and utilize these methodologies independently within the MBN Core facilities, and 4) provide behavioral and histopathologic data to the Data Management, Biostatistics, and Epidemiology (DMBE) Core from projects and studies performed within the MBN Core. The DMBE will then store/analyze these data, determine any correlations/inter-relationships between behavioral and histopathologic data in any given study, and provide any interfacing statistical analyses between MBN data (e.g., Project #3) and that attained from related clinical projects (e.g., Project #2). The work of this Core is absolutely essential for investigating Alzheimer's disease mechanisms, genetics, risk factors and treatments in the context of this ADRC proposal.

Although retrospective studies suggest that a lifelong pattern of high mental activity is protective against Alzheimer's Disease (AD), prospective longitudinal studies have not been done. As well, the contribution of social and/or physical activity to AD risk-reduction has not been adequately evaluated in controlled clinical studies nor has the potential benefit of long-term, intensive cognitive rehabilitation in AD patients. The availability of AD transgenic mice make it possible to investigate these issues in fully-controlled longitudinal studies. Our preliminary studies indicate that "complete" environmental enrichment (e.g., cognitive, social, and physical activity) is both protective and therapeutic against cognitive impairment in AD transgenic mice ? this, without affecting brain beta-amyloid deposition. The present project will first elucidate the role of each contributing component (e.g., cognitive,social, and physical) to the protective ability of complete environmental enrichment; this isolation of enrichment's contributing components is impossible to achieve in clinical studies. Second, this project will evaluate the potential of both continous and session-restricted environmental enrichment as a treatment to cognitively-impaired AD transgenic mice. All cognitive rehabilitative therapeutic in AD patients are session-restricted, so it is important to investigate this protocol in AD transgenic models. Third, a variety of brain neuropathologic and neurochemical processes will be assessed that could be mechanistically involved in the cognitive benefits provided by environmental enrichment or it's various component activities. These processes include neurogenesis, neurodegeneration, oxidative stress, neuroinflammation, and growth factor modulation. Collectively, the studies of this project are of substantial public health significance because they investigate the potential for "modifiable" factors (cognitive, social, physical activity) to protective against or treat AD, as well as provide important insight into likely cellular/molecular mechanisms that may be involved therein.

ABSTRACT Formation of misfolded protein oligomers in neurons is an early and causative event in a variety of neurodegenerative diseases, such as Alzheimer?s Disease (?-amyloid and tau oligomers), Fronto-temporal lobe dementia (tau oligomers), and Parkinson?s Disease (?-synuclein oligomers). These toxic oligomers share a common aggregation mechanism that involves formation of hydrogen bonds between individual monomers. A therapeutic that can disaggregate these oligomers, or prevent their formation from monomers, could therefore have extraordinary potential to treat a host of neurodegenerative diseases/disorders. Regarding Alzheimer?s Disease (AD), currently available therapeutics (e.g., AChE inhibitors and memantine) only temporarily slow the rate of cognitive decline without affecting the disease process. This may be in large part because these drugs have not been shown to penetrate the brain?s neurons to disaggregate toxic ?-amyloid (A?) oligomers and tau oligomers therein. The critical importance of addressing the oligomeric forms of A? and tau in AD pathogenesis, along with the failure of many clinical studies using anti-A? aggregating drugs, highlight the need for new, innovative therapies. Since 2007, Dr. Gary Arendash (NeuroEM?s PI) and his collaborators have been developing and testing a new non-pharmacologic intervention against AD ? Transcranial Electromagnetic Treatment (TEMT). In multiple peer-reviewed papers, he has demonstrated in both in vitro and in vivo studies using AD transgenic mice that TEMT prevents and reverses A? oligomerization/aggregation, both inside and outside neurons. These anti-aggregating effects demonstrate that TEMT penetrates the brain parenchyma and neurons to destabilize A? aggregates. The result is a prevention/reversal of cognitive deficits in AD transgenic mice. This proposal?s Aims will focus on administering TEMT through a new prototype head device developed for human TEMT administration against AD. To effectively validate and greatly extend our approach, Aim 1 will utilize assays for oligomeric forms of A?, tau, and ?-synuclein to specifically measure TEMT?s effects on each of these three toxic oligomers in CSF samples placed within a human head mannequin. Aim 2 will then seek to optimize the TEMT parameters for maximum anti-oligomerization and investigate direct mechanisms of TEMT action. The successful execution of these Aims will provide validation of the ?direct? anti-oligomerization effects of TEMT across toxic proteins involved in multiple neurodegenerative diseases. In a follow-up SBIR Fast Track application, NeuroEM will continue this work by: 1) investigating the ?indirect? effects of TEMT in neuronal cell cultures over-expressing these oligomers and 2) performing a Phase II clinical trial involving TEMT administration to AD patients utilizing the optimal set of TEMT parameters. Thus, the extent of both direct and indirect TEMT actions across multiple pathologic oligomers will be determined, as will insight into the anti-oligomerization mechanisms of TEMT action ? all this, utilizing a TEMT head device that we will utilize in a Phase I AD clinical trial starting in Summer 2016 that involves our current set of TEMT parameters.