Motor Cortex Theta and Gamma Architecture in Young Adult APPswePS1dE9 Alzheimer Mice.

Anna Papazoglou,Andreas Lundt,Kan Xie,Britta Haenisch,Julien Soos,Christina Henseler,Marco Weiergräber,Dan Ehninger,Ralf Müller,Karl Broich,Carola Wormuth,Varun Raj Ginde

doi:10.1371/journal.pone.0169654

Abstract

Alzheimer’s disease (AD) is a multifactorial disorder leading to progressive memory loss and eventually death. In this study, an APPswePS1dE9 AD mouse model has been analyzed for motor cortex theta, beta and gamma frequency alterations using computerized 3D stereotaxic electrode positioning and implantable video-EEG radiotelemetry to perform long-term M1 recordings from both genders considering age, circadian rhythm and activity status of experimental animals. We previously demonstrated that APPswePS1dE9 mice exibit complex alterations in hippocampal frequency power and another recent investigation reported a global increase of alpha, beta and gamma power in APPswePS1dE9 in females of 16–17 weeks of age. In this cortical study in APPswePS1dE9 mice we did not observe any changes in theta, beta and particularly gamma power in both genders at the age of 14, 15, 18 and 19 weeks. Importantly, no activity dependence of theta, beta and gamma activity could be detected. These findings clearly point to the fact that EEG activity, particularly gamma power exhibits developmental changes and spatial distinctiveness in the APPswePS1dE9 mouse model of Alzheimer’s disease.

Highlights

Alzheimer’s disease (AD) is a multifactorial neurodegenerative disorder resulting in progressive cognitive decline and memory loss
Note that no differences in relative activity could be detected for any of the ages and circadian cycles studied in APPswePS1dE9 mice and controls [31]
In contrast to the complex alterations in hippocampal theta which we reported previously, no significant alterations were detected in motor cortex (M1) theta activity in APPswePS1dE9

Summary

Introduction

Alzheimer’s disease (AD) is a multifactorial neurodegenerative disorder resulting in progressive cognitive decline and memory loss. AD is characterized by extracellular amyloid plaques based on the excessive accumulation of amyloid beta (Aβ) peptides in the central nervous system (CNS) [1,2,3]. Aβ peptides are cleavage products derived from the amyloid precursor protein (APP) via sequential endoproteolysis by specific secretases, i.e. beta-site amyloid precursor protein cleaving enzyme 1 (BACE-1) and γ-secretase [4]. The length of Aβ peptides ranges from 36–43 amino acids [5]. PLOS ONE | DOI:10.1371/journal.pone.0169654 January 10, 2017

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