Resting state functional network disruptions in a kainic acid model of temporal lobe epilepsy

Neuroimage Clin. 2016 Nov 3;13:70-81. doi: 10.1016/j.nicl.2016.11.002. eCollection 2017.

Abstract

We studied the graph topological properties of brain networks derived from resting-state functional magnetic resonance imaging in a kainic acid induced model of temporal lobe epilepsy (TLE) in rats. Functional connectivity was determined by temporal correlation of the resting-state Blood Oxygen Level Dependent (BOLD) signals between two brain regions during 1.5% and 2% isoflurane, and analyzed as networks in epileptic and control rats. Graph theoretical analysis revealed a significant increase in functional connectivity between brain areas in epileptic than control rats, and the connected brain areas could be categorized as a limbic network and a default mode network (DMN). The limbic network includes the hippocampus, amygdala, piriform cortex, nucleus accumbens, and mediodorsal thalamus, whereas DMN involves the medial prefrontal cortex, anterior and posterior cingulate cortex, auditory and temporal association cortex, and posterior parietal cortex. The TLE model manifested a higher clustering coefficient, increased global and local efficiency, and increased small-worldness as compared to controls, despite having a similar characteristic path length. These results suggest extensive disruptions in the functional brain networks, which may be the basis of altered cognitive, emotional and psychiatric symptoms in TLE.

Keywords: Default mode network; Functional connectivity; Kainic acid; Limbic system; Resting-state networks; Temporal lobe epilepsy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cerebral Cortex / diagnostic imaging
  • Cerebral Cortex / physiopathology*
  • Connectome / methods*
  • Disease Models, Animal
  • Epilepsy, Temporal Lobe / chemically induced
  • Epilepsy, Temporal Lobe / diagnostic imaging
  • Epilepsy, Temporal Lobe / physiopathology*
  • Excitatory Amino Acid Agonists / pharmacology
  • Kainic Acid / pharmacology
  • Limbic System / diagnostic imaging
  • Limbic System / physiopathology*
  • Male
  • Nerve Net / diagnostic imaging
  • Nerve Net / physiopathology*
  • Rats
  • Rats, Long-Evans

Substances

  • Excitatory Amino Acid Agonists
  • Kainic Acid