title: Is anoxic depolarisation associated with an ADC threshold? A Markov chain Monte Carlo analysis.
abstract: 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.
authors.affiliation: RCS Unit of Biophysics, Institute of Child Health, University College London, London WC1N 1EH, UK. m.king@ich.ucl.ac.uk
authors.forename: Martin D
authors.initials: MD
authors.lastname: King
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Crowder
authors.forename: David J
authors.initials: DJ
authors.lastname: Hand
authors.forename: Neil G
authors.initials: NG
authors.lastname: Harris
authors.forename: Stephen R
authors.initials: SR
authors.lastname: Williams
authors.forename: Tihomir P
authors.initials: TP
authors.lastname: Obrenovitch
authors.forename: David G
authors.initials: DG
authors.lastname: Gadian
mesh_terms: D000465:Algorithms; D000818:Animals; D004058:Diffusion; D020925:Hypoxia-Ischemia, Brain / Q000378:metabolism*; D008390:Markov Chains; D009010:Monte Carlo Method; D051381:Rats