The GABAA receptor complex in experimental absence seizures in rat: an autoradiographic study.
The regional distribution of radioactive ligand binding for different receptors of the gamma-aminobutyric acid A (GABAA)-benzodiazepine-picrotoxin chloride channel complex was measured on tissue section by autoradiography in brains taken from a genetic strain of Wistar rats with spontaneous absence-like seizures, the genetic absence epilepsy rats from Strasbourg (GAERS), and a control colony. The ligands employed included [3H]muscimol for high affinity GABA agonists sites; [3H]SR 95531 for the low-affinity GABA sites; [3H]flunitrazepam for the benzodiazepine sites; and [35S]t-butyl bicyclophosphorothionate (TBPS) for the picrotoxin site. There was no significant change between GAERS and control animals in [3H]flunitrazepam and [35S]TBPS binding. However, there was significantly decreased [3H]muscimol and [3H]SR 95531 binding in the CA2 region of the hippocampus of the GAERS. This was due to a decrease in Bmax of both [3H]muscimol and [3H]SR 95531 binding in the epileptic strain.
Snead
O C
OC
Childrens Hospital Los Angeles, Department of Neurology, University of Southern California School of Medicine 90027.
Depaulis
A
A
Banerjee
P K
PK
Hechler
V
V
Vergnes
M
M
D000818:Animals; D001345:Autoradiography; D001921:Brain / Q000378:metabolism*; D001643:Bridged Bicyclo Compounds / Q000378:metabolism*; D019086:Bridged Bicyclo Compounds, Heterocyclic; D018118:Chloride Channels; D002712:Chlorides / Q000378:metabolism*; D003292:Convulsants / Q000378:metabolism; D004832:Epilepsy, Absence / Q000235:genetics / Q000378:metabolism*; D005445:Flunitrazepam / Q000378:metabolism*; D058787:GABA-A Receptor Antagonists; D007473:Ion Channels / Q000378:metabolism; D007476:Ionophores / Q000378:metabolism*; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism; D009118:Muscimol / Q000378:metabolism*; D009928:Organ Specificity; D011712:Pyramidal Tracts / Q000378:metabolism; D011724:Pyridazines / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D011963:Receptors, GABA-A / Q000378:metabolism*; D013462:Sulfur Radioisotopes; D014316:Tritium
D001643:Bridged Bicyclo Compounds; D019086:Bridged Bicyclo Compounds, Heterocyclic; D018118:Chloride Channels; D002712:Chlorides; D003292:Convulsants; D058787:GABA-A Receptor Antagonists; C062606:GABA-benzodiazepine receptor-chloride ionophore complex; D007473:Ion Channels; D007476:Ionophores; D008565:Membrane Proteins; D011724:Pyridazines; D011963:Receptors, GABA-A; D013462:Sulfur Radioisotopes; D014316:Tritium; D009118:Muscimol; D005445:Flunitrazepam; C037476:tert-butylbicyclophosphorothionate; C049853:gabazine