Altered expression of NPY-Y1 receptors in kainic acid induced epilepsy in rats.
Kainic acid-induced limbic seizures cause lasting increases in neuropeptide Y (NPY) expression in hippocampal granule cells/mossy fibers. The expression of NPY-Y1 receptors in these neurons were investigated, using in situ hybridization for Y1 mRNA and receptor autoradiography with the Y1-specific ligand [125I][Pro34]PYY. Six hours after kainic acid-induced seizures, Y1 receptor mRNA levels decreased by 80% in granule cells and concomitantly increased (by 75%) in CA2 pyramidal neurons. Subsequently, persistent decreases in Y1 mRNA were seen, both in the stratum granulosum and in CA2. Changes in mRNA concentrations were accompanied by a transient, although non-significant, increase in [125I][Pro34]PYY binding in the molecular layer of the dentate gyrus after 4-6 h which was succeeded by a lasting decrease in binding which indicates a persistent down-regulation of Y1 receptors in hippocampal areas in kainic acid-induced epilepsy.
Kofler
N
N
Department of Pharmacology, University of Innsbruck, Austria.
Kirchmair
E
E
Schwarzer
C
C
Sperk
G
G
D000818:Animals; D001345:Autoradiography; D018891:Dentate Gyrus / Q000378:metabolism; D004827:Epilepsy / Q000139:chemically induced / Q000378:metabolism*; D006624:Hippocampus / Q000378:metabolism*; D007457:Iodine Radioisotopes; D007608:Kainic Acid; D008297:Male; D009474:Neurons / Q000378:metabolism*; D019894:Peptide YY; D010455:Peptides / Q000378:metabolism; D017966:Pyramidal Cells / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D017476:Receptors, Neuropeptide Y / Q000096:biosynthesis*; D013997:Time Factors; D014158:Transcription, Genetic
D007457:Iodine Radioisotopes; D010455:Peptides; D012333:RNA, Messenger; D017476:Receptors, Neuropeptide Y; C097212:neuropeptide Y-Y1 receptor; D019894:Peptide YY; D007608:Kainic Acid