Abnormal excitability of oblique dendrites implicated in early Alzheimer's: a computational study

Autor: Tom Morse, Nicholas T Carnevale, Pradeep Mutalik, Michele Migliore, Gordon M Shepherd
Jazyk: angličtina
Rok vydání: 2010
Předmět:
Zdroj: Frontiers in Neural Circuits, Vol 4 (2010)
Druh dokumentu: article
ISSN: 1662-5110
DOI: 10.3389/fncir.2010.00016
Popis: The integrative properties of cortical pyramidal dendrites are essential to the neural basis of cognitive function, but the impact of amyloid beta protein (aβ) on these properties in early Alzheimer's is poorly understood. In animal models, electrophysiological studies of proximal dendrites have shown that aβ induces hyperexcitability by blocking A-type K+ currents (IA), disrupting signal integration. The present study uses a computational approach to analyse the hyperexcitability induced in distal dendrites beyond the experimental recording sites. The results show that back-propagating action potentials in the dendrites induce hyperexcitability and excessive calcium concentrations not only in the main apical trunk of pyramidal cell dendrites, but also in their oblique dendrites. Evidence is provided that these thin branches are particularly sensitive to local reductions in IA. The results suggest the hypothesis that the oblique branches may be most vulnerable to disruptions of IA by early exposure to aβ, and point the way to further experimental analysis of these actions as factors in the neural basis of the early decline of cognitive function in Alzheimer's.
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