Seizure activity selectively reduces 5-HT1A receptor immunoreactivity in CA1 interneurons in the hippocampus of seizure-prone gerbils.
Since the correlation between the serotonin (5-hydroxytryptamine, 5-HT) system and seizure activity remains to be clarified, we investigated the 5-HT system in the hippocampus of seizure-resistant (SR) and seizure-sensitive (SS) gerbils. There was no difference of the 5-HT system in the hippocampi of young animals (predisposed and juvenile gerbils) in both SR and SS gerbils. 5-HT immunoreactivity in the dorsal raphe nucleus and the median raphe nucleus was also similarly detected in both animal groups. As compared to SR adult gerbils, only 5-HT1A receptor immunoreactivity was selectively reduced in CA1 interneurons within SS adult gerbils. (+/-)-8-hydroxy-2-(di-n-propylamino)tetralin (a 5-HT1A receptor agonist, 1 and 2 mg/kg) markedly reduced paired-pulse inhibition in the CA1 region of SS adult gerbils only. These findings suggest that the selective reduction in 5-HT1A receptor expression on CA1 interneurons of SS adult gerbil may not be developmental defects, but be an acquired compensatory change induced by repeated seizure activity.
Kim
Duk-Soo
DS
Department of Anatomy, College of Medicine, Hallym University, Chunchon 200-702, South Korea.
Kim
Ji-Eun
JE
Kwak
Sung-Eun
SE
Kim
Dae-Won
DW
Choi
Soo-Young
SY
Kwon
Oh-Shin
OS
Kang
Tae-Chon
TC
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D000704:Analysis of Variance; D000818:Animals; D002452:Cell Count / Q000379:methods; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004569:Electroencephalography / Q000379:methods; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology*; D005849:Gerbillinae; D005968:Glutamate Decarboxylase / Q000378:metabolism; D006624:Hippocampus / Q000473:pathology*; D007395:Interneurons / Q000378:metabolism*; D007527:Isoenzymes / Q000378:metabolism; D044282:Receptor, Serotonin, 5-HT1A / Q000378:metabolism*; D012640:Seizures / Q000139:chemically induced / Q000473:pathology* / Q000503:physiopathology*; D012701:Serotonin / Q000378:metabolism; D050486:Serotonin Plasma Membrane Transport Proteins / Q000378:metabolism
D007527:Isoenzymes; D050486:Serotonin Plasma Membrane Transport Proteins; D044282:Receptor, Serotonin, 5-HT1A; D012701:Serotonin; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D005968:Glutamate Decarboxylase; C402565:glutamate decarboxylase 1