AUTHOR=Kalweit Alexander Nikolai , Yang Honghong , Colitti-Klausnitzer Jens , Fülöp Livia , Bozsó Zsolt , Penke Botond , Manahan-Vaughan Denise 

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

JOURNAL=Frontiers in Behavioral Neuroscience

VOLUME=Volume 9 - 2015

YEAR=2015

URL=https://www.frontiersin.org/journals/behavioral-neuroscience/articles/10.3389/fnbeh.2015.00103

DOI=10.3389/fnbeh.2015.00103

ISSN=1662-5153

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 occur 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 results in LTP failure, 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 24h. 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 and the characteristic profiles of theta-gamma oscillations that accompany successful LTP induction were 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.