Increased expression of "peripheral-type" benzodiazepine receptors in human temporal lobe epilepsy: implications for PET imaging of hippocampal sclerosis.
Increased binding sites for "peripheral-type" benzodiazepine receptor (PTBR) ligands have been described in a wide range of neurological disorders including both human and experimental epilepsy. This study was undertaken to assess PTBR expression in relation to the presence of hippocampal sclerosis in human temporal lobe epilepsy (TLE). For this purpose, hippocampal CA1 subfields were dissected from surgical samples from patients with therapy-refractive TLE with (n = 5) or without (n = 2) hippocampal sclerosis and from age-matched nonepileptic postmortem controls (n = 5). PTBR expression was assessed by immunohistochemistry and reverse-transcription polymerase chain reaction. Receptor sites were evaluated using an in vitro binding assay and the selective PTBR ligand [3H]PK11195. Epileptic patients with hippocampal sclerosis showed increases in PTBR binding sites, immunoreactivity, and mRNA expression compared to both nonsclerotic TLE patients and postmortem nonepileptic controls. Induction of PTBR expression and binding sites were directly correlated with the presence of hippocampal sclerosis and the accompanying reactive gliosis.
Sauvageau
Anny
A
Neuroscience Research Unit, CHUM, Montreal, Quebec, Canada.
Desjardins
Paul
P
Lozeva
Violina
V
Rose
Christopher
C
Hazell
Alan S
AS
Bouthillier
Alain
A
Butterwort
Roger F
RF
D004833:Epilepsy, Temporal Lobe / Q000000981:diagnostic imaging* / Q000378:metabolism*; D006624:Hippocampus / Q000166:cytology / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D007546:Isoquinolines; D007700:Kinetics; D009474:Neurons / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D011963:Receptors, GABA-A / Q000096:biosynthesis*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012598:Sclerosis; D013570:Synaptic Membranes / Q000378:metabolism; D014055:Tomography, Emission-Computed
D007546:Isoquinolines; D012333:RNA, Messenger; D011963:Receptors, GABA-A; C037850:PK 11195