Journal Article


K.J Friston
R.B Reilly
K.J Murphy
William T. O'Connor
N Rombach
S.J Kiebel
K.E Stephan
R.J Moran



schizophrenia rats wistar steady state gaba expectation maximization em glutamate bayesian estimation dynamic causal modelling

Bayesian estimation of synaptic physiology from the spectral responses of neural masses (2008)

Abstract 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 parameter 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 concomitant microdialysis measures. The modelling of the LFP 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. (c) 2008 Elsevier Inc. All rights reserved.
Collections Ireland -> University of Limerick -> Graduate Entry Medical School
Ireland -> University of Limerick -> Faculty of Education & Health Sciences
Ireland -> University of Limerick -> Departments Education & Health Sciences

Full list of authors on original publication

K.J Friston, R.B Reilly, K.J Murphy, William T. O'Connor, N Rombach, S.J Kiebel, K.E Stephan, R.J Moran

Experts in our system

Richard Reilly
Trinity College Dublin
Total Publications: 185
William T. O'Connor
University College Dublin
Total Publications: 21