Premium
Lateral entorhinal cortex lesions rearrange afferents, glutamate receptors, increase seizure latency and suppress seizure‐induced c‐ fos expression in the hippocampus of adult rat
Author(s) -
Kopniczky Zsolt,
Dobó Endre,
Borbély Sándor,
Világi Ildikó,
Détári László,
KrisztinPéva Beáta,
Bagosi Andrea,
Molnár Elek,
Mihály András
Publication year - 2005
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.2005.03347.x
Subject(s) - neuroscience , hippocampal formation , dentate gyrus , entorhinal cortex , kainate receptor , hippocampus , epileptogenesis , ampa receptor , glutamate receptor , lesion , calretinin , nmda receptor , biology , chemistry , receptor , medicine , pathology , biochemistry , immunohistochemistry , immunology
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, GluR1 flop 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.