Increased binding of inhibitory neuronal receptors in the hippocampus in kainate-treated rats with spontaneous limbic seizures.
To gain a better understanding of the relationship between epileptogenicity and inhibitory neuronal mechanisms, we examined variations in A1 adenosine (A1A) receptor binding in the hippocampi of rats with spontaneous limbic seizures in the chronic phase after systemic kainic acid treatment. Six weeks after kainate treatment, rats with spontaneous limbic seizures were killed for histological and in vitro autoradiographic analyses of the brain. The analyses were performed using [(3)H] 8-cyclopentyl-1,3-dipropylxanthine (DPCPX), an A1A receptor antagonist. Relative to controls, DPCPX binding was increased in the CA3 region and in the molecular layer of the dentate gyrus in the kainate-treated rats. This is the first evidence of upregulation of the A1A receptor in a model of chronic temporal lobe epilepsy. Increased binding of the A1A receptor may contribute to epileptogenesis in the epileptic focus.
Ohta
Yoshihisa
Y
Department of Neurosurgery, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan. ohta@matsuzawa-hp.metro.tokyo.jp <ohta@matsuzawa-hp.metro.tokyo.jp>
Nariai
Tadashi
T
Kurumaji
Akeo
A
Hirakawa
Kimiyoshi
K
Ohno
Kikuo
K
D000704:Analysis of Variance; D000818:Animals; D001345:Autoradiography; D006624:Hippocampus / Q000378:metabolism* / Q000473:pathology; D007608:Kainic Acid; D008297:Male; D009474:Neurons / Q000378:metabolism* / Q000473:pathology; D011869:Radioligand Assay; D051381:Rats; D017208:Rats, Wistar; D043682:Receptor, Adenosine A1 / Q000378:metabolism*; D011963:Receptors, GABA-A / Q000378:metabolism*; D012640:Seizures / Q000139:chemically induced* / Q000378:metabolism / Q000473:pathology
D043682:Receptor, Adenosine A1; D011963:Receptors, GABA-A; D007608:Kainic Acid