Title
Beta-amyloid induced changes in A-type K⁺ current can alter hippocampo-septal network dynamics.
Abstract
Alzheimer's disease (AD) progression is usually associated with memory deficits and cognitive decline. A hallmark of AD is the accumulation of beta-amyloid (Aβ) peptide, which is known to affect the hippocampal pyramidal neurons in the early stage of AD. Previous studies have shown that Aβ can block A-type K(+) currents in the hippocampal pyramidal neurons and enhance the neuronal excitability. However, the mechanisms underlying such changes and the effects of the hyper-excited pyramidal neurons on the hippocampo-septal network dynamics are still to be investigated. In this paper, Aβ-blocked A-type current is simulated, and the resulting neuronal and network dynamical changes are evaluated in terms of the theta band power. The simulation results demonstrate an initial slight but significant theta band power increase as the A-type current starts to decrease. However, the theta band power eventually decreases as the A-type current is further decreased. Our analysis demonstrates that Aβ blocked A-type currents can increase the pyramidal neuronal excitability by preventing the emergence of a steady state. The increased theta band power is due to more pyramidal neurons recruited into spiking mode during the peak of pyramidal theta oscillations. However, the decreased theta band power is caused by the spiking phase relationship between different neuronal populations, which is critical for theta oscillation, is violated by the hyper-excited pyramidal neurons. Our findings could provide potential implications on some AD symptoms, such as memory deficits and AD caused epilepsy.
Year
DOI
Venue
2012
10.1007/s10827-011-0363-7
Journal of Computational Neuroscience
Keywords
Field
DocType
Alzheimer’s disease,β-Amyloid,A-type K,+,current,Phase-plane analysis,Hippocampo-septal theta rhythm
Neuroscience,Membrane potential,Network dynamics,Amyloid,Nerve net,Potassium channel,Beta (finance),Hippocampal formation,Mathematics,Cognitive decline
Journal
Volume
Issue
ISSN
32
3
1573-6873
Citations 
PageRank 
References 
2
0.40
1
Authors
4
Name
Order
Citations
PageRank
Xin Zou1141.83
Damian Coyle227131.55
KongFatt Wong-Lin34611.52
Liam Maguire415011.56