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Computational Intelligence and Neuroscience
Volume 2013 (2013), Article ID 949816, 19 pages
http://dx.doi.org/10.1155/2013/949816
Research Article

Enhanced Synaptic Connectivity in the Dentate Gyrus during Epileptiform Activity: Network Simulation

1Laboratório de Neurociência Experimental e Computacional, Departamento de Engenharia de Biossistemas, Universidade Federal de São João del-Rei (UFSJ), Brazil
2Programa de Engenharia Biomédica, Universidade Federal do Rio de Janeiro (UFRJ/COPPE), Brazil
3Disciplina de Neurologia Experimental, Escola Paulista de Medicina (EPM), Universidade Federal de São Paulo (UNIFESP), Brazil
4Disciplina de Neurofisiologia e Fisiologia do Exercício, Escola Paulista de Medicina (EPM), Universidade Federal de São Paulo (UNIFESP), Brazil

Received 7 August 2012; Revised 6 December 2012; Accepted 20 December 2012

Academic Editor: Steven Bressler

Copyright © 2013 Keite Lira de Almeida França et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Structural rearrangement of the dentate gyrus has been described as the underlying cause of many types of epilepsies, particularly temporal lobe epilepsy. It is said to occur when aberrant connections are established in the damaged hippocampus, as described in human epilepsy and experimental models. Computer modelling of the dentate gyrus circuitry and the corresponding structural changes has been used to understand how abnormal mossy fibre sprouting can subserve seizure generation observed in experimental models when epileptogenesis is induced by status epilepticus. The model follows the McCulloch-Pitts formalism including the representation of the nonsynaptic mechanisms. The neuronal network comprised granule cells, mossy cells, and interneurons. The compensation theory and the Hebbian and anti-Hebbian rules were used to describe the structural rearrangement including the effects of the nonsynaptic mechanisms on the neuronal activity. The simulations were based on neuroanatomic data and on the connectivity pattern between the cells represented. The results suggest that there is a joint action of the compensation theory and Hebbian rules during the inflammatory process that accompanies the status epilepticus. The structural rearrangement simulated for the dentate gyrus circuitry promotes speculation about the formation of the abnormal mossy fiber sprouting and its role in epileptic seizures.