Alzheimer's disease (AD) and other age-related neurodegenerative disorders are a major source of morbidity and mortality. In the U.S. alone, some 5 million people have AD, a relentless and fatal condition that devastates the mind and engenders feelings of hopelessness in caregivers. The urgency in finding a cure for AD has never been stronger. AD is associated with an increased incidence of seizures as well as cognitive decline. Seizures and subclinical excitatory neuronal activity may contribute to cognitive deficits. We propose to investigate neuroprotective strategies to counter neuronal overexcitation and seizures in AD and identify a population who could benefit from such therapies. The laboratory investigation focuses on the axonal transport of two cellular components that tightly regulate neuronal activity-mitochondria and the voltage-gated potassium channel Kv1.1. The neurotoxic peptide amyloid-? (A?) impairs axonal transport of mitochondria, and reduction of the microtubule-associated protein tau completely abolishes this effect. Tau reduction also protects against seizures and behavioral deficits in transgenic mouse models of AD. These findings suggest a pathogenic mechanism for A? and tau involving axonal transport and neuronal excitability.
In Aim 1, we will investigate mechanisms by which tau and A? regulate the axonal transport of mitochondria and Kv1.1, and study the effects of tau reduction on axonal transport of these cargoes in vivo in a mouse model of AD.
Aim 2 is a translational clinical investigation of the extent of subclinical epileptiform activity in people with mild cognitive impairment and AD with an eye toward future therapeutic trials using antiepileptic medications or tau-targeted strategies. The candidate is a physician-scientist with a strong commitment to a career in academic neurology focused on identifying novel therapies for AD and related dementias. The candidate has an MSc in biomedical engineering and an MD with clinical training in neurology and subspecialty training in behavioral neurology and neurodegenerative dementias. The research proposal and career development plan build upon his training in neuroscience, aging, and neurodegenerative diseases to provide expertise in transgenic mouse models of AD, histology, cell culture, microfluidics chambers, time-lapse microscopy, transcranial two-photon imaging, and translational clinical trials. Dr. Lennart Mucke, a physician-scientist who cares for patients with dementia and specializes in transgenic mouse models of neurodegenerative disease, is the candidate's sponsor. The mentoring and research experience described in this proposal will facilitate the candidate's goal of developing a strong independent research career.

Public Health Relevance

Projected increases in the prevalence of dementia with the aging of the American population are a major threat to our healthcare system, and the development of novel therapeutic approaches is a critical goal. This project is designed to uncover mechanisms by which tau reduction is protective against neural network dysfunction and seizures in mouse models of AD and to identify people in the early stages of AD who have subclinical epileptiform activity and who could benefit from tau-targeted strategies or antiepileptic drugs. A host of FDA-approved antiepileptic medications are already available that could be tested in future clinical trials.

National Institute of Health (NIH)
National Institute on Aging (NIA)
Mentored Patient-Oriented Research Career Development Award (K23)
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Special Emphasis Panel (ZAG1)
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Petanceska, Suzana
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J. David Gladstone Institutes
San Francisco
United States
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Ranasinghe, Kamalini G; Rankin, Katherine P; Pressman, Peter S et al. (2016) Distinct Subtypes of Behavioral Variant Frontotemporal Dementia Based on Patterns of Network Degeneration. JAMA Neurol 73:1078-88
Ossenkoppele, Rik; Schonhaut, Daniel R; Schöll, Michael et al. (2016) Tau PET patterns mirror clinical and neuroanatomical variability in Alzheimer's disease. Brain 139:1551-67
Ranasinghe, Kamalini G; Rankin, Katherine P; Lobach, Iryna V et al. (2016) Cognition and neuropsychiatry in behavioral variant frontotemporal dementia by disease stage. Neurology 86:600-10
Vossel, Keith A; Ranasinghe, Kamalini G; Beagle, Alexander J et al. (2016) Incidence and impact of subclinical epileptiform activity in Alzheimer's disease. Ann Neurol 80:858-870
Morris, Meaghan; Sanchez, Pascal E; Verret, Laure et al. (2015) Network dysfunction in α-synuclein transgenic mice and human Lewy body dementia. Ann Clin Transl Neurol 2:1012-28
Vossel, Keith A; Xu, Jordan C; Fomenko, Vira et al. (2015) Tau reduction prevents Aβ-induced axonal transport deficits by blocking activation of GSK3β. J Cell Biol 209:419-33
Ranasinghe, Kamalini G; Hinkley, Leighton B; Beagle, Alexander J et al. (2014) Regional functional connectivity predicts distinct cognitive impairments in Alzheimer's disease spectrum. Neuroimage Clin 5:385-95
Vossel, Keith A; Bien-Ly, Nga; Bernardo, Aubrey et al. (2013) ApoE and TDP-43 neuropathology in two siblings with familial FTLD-motor neuron disease. Neurocase 19:295-301
Vossel, Keith A; Beagle, Alexander J; Rabinovici, Gil D et al. (2013) Seizures and epileptiform activity in the early stages of Alzheimer disease. JAMA Neurol 70:1158-66
Sanchez, Pascal E; Zhu, Lei; Verret, Laure et al. (2012) Levetiracetam suppresses neuronal network dysfunction and reverses synaptic and cognitive deficits in an Alzheimer's disease model. Proc Natl Acad Sci U S A 109:E2895-903