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Contribution Details

Type Journal Article
Scope Discipline-based scholarship
Title Bayesian estimation of synaptic physiology from the spectral responses of neural masses
Organization Unit
Authors
  • R J Moran
  • Klaas Enno Stephan
  • S J Kiebel
  • N Rombach
  • W T O'Connor
  • K J Murphy
  • R B Reilly
  • K J Friston
Item Subtype Original Work
Refereed Yes
Status Published in final form
Language
  • English
Journal Title NeuroImage
Publisher Elsevier
Geographical Reach international
ISSN 1053-8119
Volume 42
Number 1
Page Range 272 - 284
Date 2008
Abstract Text We describe a Bayesian inference scheme for quantifying the active physiology of neuronal ensembles using local field recordings of synaptic potentials. This entails the inversion of a generative neural mass model of steady-state spectral activity. The inversion uses Expectation Maximization (EM) to furnish the posterior probability of key synaptic parameters and the marginal likelihood of the model itself. The neural mass model embeds prior knowledge pertaining to both the anatomical [synaptic] circuitry and plausible trajectories of neuronal dynamics. This model comprises a population of excitatory pyramidal cells, under local interneuron inhibition and driving excitation from layer IV stellate cells. Under quasi-stationary assumptions, the model can predict the spectral profile of local field potentials (LFP). This means model parameters can be optimised given real electrophysiological observations. The validity of inferences about synaptic parameters is demonstrated using simulated data and experimental recordings from the medial prefrontal cortex of control and isolation-reared Wistar rats. Specifically, we examined the maximum a posteriori estimates of parameters describing synaptic function in the two groups and tested predictions derived from concomitantmicrodialysismeasures.Themodelling of theLFP recordings revealed (i) a sensitization of post-synaptic excitatory responses, particularly marked in pyramidal cells, in the medial prefrontal cortex of socially isolated rats and (ii) increased neuronal adaptation. These inferences were consistent with predictions derived from experimental microdialysis measures of extracellular glutamate levels.
Digital Object Identifier 10.1016/j.neuroimage.2008.01.025
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