title: A single dose of kainic acid elevates the levels of enkephalins and activator protein-1 transcription factors in the hippocampus for up to 1 year.
abstract: Neuronal plasticity plays a very important role in brain adaptations to environmental stimuli, disease, and aging processes. The kainic acid model of temporal lobe epilepsy was used to study the long-term anatomical and biochemical changes in the hippocampus after seizures. Using Northern blot analysis, immunocytochemistry, and Western blot analysis, we have found a long-term elevation of the proconvulsive opioid peptide, enkephalin, in the rat hippocampus. We have also demonstrated that an activator protein-1 transcription factor, the 35-kDa fos-related antigen, can be induced and elevated for at least 1 year after kainate treatment. This study demonstrated that a single systemic injection of kainate produces almost permanent increases in the enkephalin and an activator protein-1 transcription factor, the 35-kDa fos-related antigen, in the rat hippocampus, and it is likely that these two events are closely associated with the molecular mechanisms of induction of long-lasting enhanced seizure susceptibility in the kainate-induced seizure model. The long-term expression of the proenkephalin mRNA and its peptides in the kainate-treated rat hippocampus also suggests an important role in the recurrent seizures of temporal lobe epilepsy.
authors.affiliation: Neuropharmacology Section, Laboratory of Toxicology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA. bing@niehs.nih.gov
authors.forename: G
authors.initials: G
authors.lastname: Bing
authors.forename: B
authors.initials: B
authors.lastname: Wilson
authors.forename: P
authors.initials: P
authors.lastname: Hudson
authors.forename: L
authors.initials: L
authors.lastname: Jin
authors.forename: Z
authors.initials: Z
authors.lastname: Feng
authors.forename: W
authors.initials: W
authors.lastname: Zhang
authors.forename: R
authors.initials: R
authors.lastname: Bing
authors.forename: J S
authors.initials: JS
authors.lastname: Hong
mesh_terms: D000818:Animals; D004745:Enkephalins / Q000378:metabolism*; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology*; D006624:Hippocampus / Q000378:metabolism*; D007608:Kainic Acid / Q000494:pharmacology*; D008297:Male; D051381:Rats; D011916:Rats, Inbred F344; D013997:Time Factors; D018808:Transcription Factor AP-1 / Q000378:metabolism*
chemical_list: D004745:Enkephalins; D018690:Excitatory Amino Acid Agonists; D018808:Transcription Factor AP-1; D007608:Kainic Acid