Is anoxic depolarisation associated with an ADC threshold? A Markov chain Monte Carlo analysis.
A Bayesian nonlinear hierarchical random coefficients model was used in a reanalysis of a previously published longitudinal study of the extracellular direct current (DC)-potential and apparent diffusion coefficient (ADC) responses to focal ischaemia. The main purpose was to examine the data for evidence of an ADC threshold for anoxic depolarisation. A Markov chain Monte Carlo simulation approach was adopted. The Metropolis algorithm was used to generate three parallel Markov chains and thus obtain a sampled posterior probability distribution for each of the DC-potential and ADC model parameters, together with a number of derived parameters. The latter were used in a subsequent threshold analysis. The analysis provided no evidence indicating a consistent and reproducible ADC threshold for anoxic depolarisation.
King
Martin D
MD
RCS Unit of Biophysics, Institute of Child Health, University College London, London WC1N 1EH, UK. m.king@ich.ucl.ac.uk
Crowder
Martin J
MJ
Hand
David J
DJ
Harris
Neil G
NG
Williams
Stephen R
SR
Obrenovitch
Tihomir P
TP
Gadian
David G
DG
D000465:Algorithms; D000818:Animals; D004058:Diffusion; D020925:Hypoxia-Ischemia, Brain / Q000378:metabolism*; D008390:Markov Chains; D009010:Monte Carlo Method; D051381:Rats