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Dynamic causal modelling of seizure activity in a rat model.
- Source :
-
NeuroImage [Neuroimage] 2017 Feb 01; Vol. 146, pp. 518-532. Date of Electronic Publication: 2016 Sep 14. - Publication Year :
- 2017
-
Abstract
- This paper presents a physiological account of seizure activity and its evolution over time using a rat model of induced epilepsy. We analyse spectral activity recorded in the hippocampi of three rats who received kainic acid injections in the right hippocampus. We use dynamic causal modelling of seizure activity and Bayesian model reduction to identify the key synaptic and connectivity parameters that underlie seizure onset. Using recent advances in hierarchical modelling (parametric empirical Bayes), we characterise seizure onset in terms of slow fluctuations in synaptic excitability of specific neuronal populations. Our results suggest differences in the pathophysiology - of seizure activity in the lesioned versus the non-lesioned hippocampus - with pronounced changes in excitation-inhibition balance and temporal summation on the lesioned side. In particular, our analyses suggest that marked reductions in the synaptic time constant of the deep pyramidal cells and the self-inhibition of inhibitory interneurons (in the lesioned hippocampus) are sufficient to explain changes in spectral activity. Although these synaptic changes are consistent over rats, the resulting electrophysiological phenotype can be quite diverse.<br /> (Copyright © 2016 Elsevier Inc. All rights reserved.)
- Subjects :
- Animals
Bayes Theorem
Epilepsy chemically induced
Hippocampus drug effects
Kainic Acid administration & dosage
Rats, Wistar
Seizures chemically induced
Signal Processing, Computer-Assisted
Epilepsy physiopathology
Hippocampus physiopathology
Models, Neurological
Neurons physiology
Seizures physiopathology
Subjects
Details
- Language :
- English
- ISSN :
- 1095-9572
- Volume :
- 146
- Database :
- MEDLINE
- Journal :
- NeuroImage
- Publication Type :
- Academic Journal
- Accession number :
- 27639356
- Full Text :
- https://doi.org/10.1016/j.neuroimage.2016.08.062