Heterogeneous GABAA receptor subunit expression in pediatric epilepsy patients.
The gamma-amino-butyric acid type A receptors (GABAAR) are a heteropentameric receptor complex, composed of 16 possible subunits in various combinations, forming a ligand-gated ion channel. Subunit composition is the primary determinant of GABAAR physiology and pharmacology. Here we have measured mRNA levels for 16 GABAAR subunits in isolated dentate granule neurons (DGN) from eight pediatric patients undergoing resective surgery for intractable epilepsy. We found tightly correlated expression of a subset of GABAAR subunit mRNAs within a single DGN (alpha1, gamma1, and gamma2; alpha4, alpha5, and beta2; alpha4 and beta3). Analysis of inter-patient variability (ANOVA) of eleven highly expressed GABAAR subunit mRNAs found seven of the subunits varied between patients, as did whole cell GABAAR currents. Due to inter-patient differences, there is heterogeneity in DGN GABAAR subunit mRNA and physiology within pediatric epilepsy patients. Patient-specific GABAAR expression might contribute to variability in anti-epileptic drug efficacy, side-effect profiles, and seizure susceptibility.
Porter
Brenda E
BE
Division of Neurology, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA. porterb@email.chop.edu
Zhang
Guojun
G
Celix
Juanita
J
Hsu
Fu-chun
FC
Raol
YogendraSinh H
YH
Telfeian
Albert
A
Gallagher
Paul R
PR
Coulter
Douglas A
DA
Brooks-Kayal
Amy R
AR
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D004827:Epilepsy / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000502:physiology; D006624:Hippocampus / Q000378:metabolism; D006801:Humans; D021122:Protein Subunits / Q000096:biosynthesis* / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D011963:Receptors, GABA-A / Q000096:biosynthesis* / Q000235:genetics
D021122:Protein Subunits; D012333:RNA, Messenger; D011963:Receptors, GABA-A