title: Soluble pathological tau in the entorhinal cortex leads to presynaptic deficits in an early Alzheimer's disease model.
abstract: Neurofibrillary tangles (NFTs), a hallmark of Alzheimer's disease, are intracellular silver and thioflavin S-staining aggregates that emerge from earlier accumulation of phospho-tau in the soma. Whether soluble misfolded but nonfibrillar tau disrupts neuronal function is unclear. Here we investigate if soluble pathological tau, specifically directed to the entorhinal cortex (EC), can cause behavioral or synaptic deficits. We studied rTgTauEC transgenic mice, in which P301L mutant human tau overexpressed primarily in the EC leads to the development of tau pathology, but only rare NFT at 16 months of age. We show that the early tau lesions are associated with nearly normal performance in contextual fear conditioning, a hippocampal-related behavior task, but more robust changes in neuronal system activation as marked by Arc induction and clear electrophysiological defects in perforant pathway synaptic plasticity. Electrophysiological changes were likely due to a presynaptic deficit and changes in probability of neurotransmitter release. The data presented here support the hypothesis that misfolded and hyperphosphorylated tau can impair neuronal function within the entorhinal-hippocampal network, even prior to frank NFT formation and overt neurodegeneration.
authors.affiliation: Department of Neurology, Massachusetts General Hospital, Harvard Medical School, 114 16th Street Room 2009, Charlestown, MA, 02129, USA.
authors.forename: Manuela
authors.initials: M
authors.lastname: Polydoro
authors.forename: Volodymyr I
authors.initials: VI
authors.lastname: Dzhala
authors.forename: Amy M
authors.initials: AM
authors.lastname: Pooler
authors.forename: Samantha B
authors.initials: SB
authors.lastname: Nicholls
authors.forename: A Patrick
authors.initials: AP
authors.lastname: McKinney
authors.forename: Laura
authors.initials: L
authors.lastname: Sanchez
authors.forename: Rose
authors.initials: R
authors.lastname: Pitstick
authors.forename: George A
authors.initials: GA
authors.lastname: Carlson
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Staley
authors.forename: Tara L
authors.initials: TL
authors.lastname: Spires-Jones
authors.forename: Bradley T
authors.initials: BT
authors.lastname: Hyman
mesh_terms: D000544:Alzheimer Disease / Q000378:metabolism* / Q000503:physiopathology*; D000818:Animals; D003598:Cytoskeletal Proteins / Q000378:metabolism; D004195:Disease Models, Animal; D055724:Electrophysiological Phenomena / Q000502:physiology; D018728:Entorhinal Cortex / Q000378:metabolism* / Q000503:physiopathology; D006624:Hippocampus / Q000378:metabolism / Q000503:physiopathology; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009473:Neuronal Plasticity / Q000502:physiology; D017729:Presynaptic Terminals / Q000502:physiology*; D016875:tau Proteins / Q000378:metabolism*
chemical_list: D003598:Cytoskeletal Proteins; D009419:Nerve Tissue Proteins; C092069:activity regulated cytoskeletal-associated protein; D016875:tau Proteins