title: Acute intracerebral treatment with amyloid-beta (1-42) alters the profile of neuronal oscillations that accompany LTP induction and results in impaired LTP in freely behaving rats.
abstract: Accumulation of amyloid plaques comprises one of the major hallmarks of Alzheimer's disease (AD). In rodents, acute treatment with amyloid-beta (Aβ; 1-42) elicits immediate debilitating effects on hippocampal long-term potentiation (LTP). Whereas LTP contributes to synaptic information storage, information is transferred across neurons by means of neuronal oscillations. Furthermore, changes in theta-gamma oscillations, that appear during high-frequency stimulation (HFS) to induce LTP, predict whether successful LTP will occur. Here, we explored if intra-cerebral treatment with Aβ(1-42), that prevents LTP, also results in alterations of hippocampal oscillations that occur during HFS of the perforant path-dentate gyrus synapse in 6-month-old behaving rats. HFS resulted in LTP that lasted for over 24 h. In Aβ-treated animals, LTP was significantly prevented. During HFS, spectral power for oscillations below 100 Hz (δ, θ, α, β and γ) was significantly higher in Aβ-treated animals compared to controls. In addition, the trough-to-peak amplitudes of theta and gamma cycles were higher during HFS in Aβ-treated animals. We also observed a lower amount of envelope-to-signal correlations during HFS in Aβ-treated animals. Overall, the characteristic profile of theta-gamma oscillations that accompany successful LTP induction was disrupted. These data indicate that alterations in network oscillations accompany Aβ-effects on hippocampal LTP. This may comprise an underlying mechanism through which disturbances in synaptic information storage and hippocampus-dependent memory occurs in AD.
authors.affiliation: Medical Faculty, Department of Neurophysiology, Ruhr University Bochum Bochum, Germany ; International Graduate School of Neuroscience, Ruhr University Bochum Bochum, Germany.
authors.forename: Alexander Nikolai
authors.initials: AN
authors.lastname: Kalweit
authors.affiliation: Medical Faculty, Department of Neurophysiology, Ruhr University Bochum Bochum, Germany ; International Graduate School of Neuroscience, Ruhr University Bochum Bochum, Germany.
authors.forename: Honghong
authors.initials: H
authors.lastname: Yang
authors.affiliation: Medical Faculty, Department of Neurophysiology, Ruhr University Bochum Bochum, Germany.
authors.forename: Jens
authors.initials: J
authors.lastname: Colitti-Klausnitzer
authors.affiliation: Department of Medical Chemistry, University of Szeged Szeged, Hungary.
authors.forename: Livia
authors.initials: L
authors.lastname: Fülöp
authors.affiliation: Department of Medical Chemistry, University of Szeged Szeged, Hungary.
authors.forename: Zsolt
authors.initials: Z
authors.lastname: Bozsó
authors.affiliation: Department of Medical Chemistry, University of Szeged Szeged, Hungary.
authors.forename: Botond
authors.initials: B
authors.lastname: Penke
authors.affiliation: Medical Faculty, Department of Neurophysiology, Ruhr University Bochum Bochum, Germany ; International Graduate School of Neuroscience, Ruhr University Bochum Bochum, Germany.
authors.forename: Denise
authors.initials: D
authors.lastname: Manahan-Vaughan
keywords: Alzheimer’s disease; amyloid beta; cognitive deficits; hippocampus; oscillations