Lateral entorhinal cortex lesions rearrange afferents, glutamate receptors, increase seizure latency and suppress seizure-induced c-fos expression in the hippocampus of adult rat

Zsolt Kopniczky, Endre Dobó, Sándor Borbély, Ildikó Világi, László Détári, Beáta Krisztin-Péva, Andrea Bagosi, Elek Molnár, András Mihály

Research output: Contribution to journalArticle

22 Citations (Scopus)

Abstract

The entorhinal cortex (EC) provides the predominant excitatory drive to the hippocampal CA1 and subicular neurones in chronic epilepsy. Here we analysed the effects of one-sided lateral EC (LEC) and temporoammonic (alvear) path lesion on the development and properties of 4-aminopyridine-induced seizures. Electroencephalography (EEG) analysis of freely moving rats identified that the lesion increased the latency of the hippocampal seizure significantly and decreased the number of brief convulsions. Seizure-induced neuronal c-fos expression was reduced in every hippocampal area following LEC lesion. Immunocytochemical analysis 40 days after the ablation of the LEC identified sprouting of cholinergic and calretinin-containing axons into the dentate molecular layer. Region and subunit specific changes in the expression of ionotropic glutamate receptors (iGluRs) were identified. Although the total amount of AMPA receptor subunits remained unchanged, GluR1flop displayed a significant decrease in the CA1 region. An increase in NR1 and NR2B N-methyl-D-aspartate (NMDA) receptor subunits and KA-2 kainate receptor subunit was identified in the deafferented layers of the hippocampus. These results further emphasize the importance of the lateral entorhinal area in the spread and regulation of hippocampal seizures and highlight the potential role of the rewiring of afferents and rearrangement of iGluRs in the dentate gyrus in hippocampal convulsive activity.

Original languageEnglish
Pages (from-to)111-124
Number of pages14
JournalJournal of neurochemistry
Volume95
Issue number1
DOIs
Publication statusPublished - Oct 1 2005

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Keywords

  • 4-aminopyridine
  • Entorhinal cortex
  • Hippocampus
  • Seizure
  • Sprouting
  • c-fos

ASJC Scopus subject areas

  • Biochemistry
  • Cellular and Molecular Neuroscience

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