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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2010-9-6
pubmed:abstractText
The neurodevelopmental disorder Angelman syndrome is most frequently caused by deletion of the maternally derived chromosome 15q11-q13 region, which includes not only the causative UBE3A gene, but also the beta(3)-alpha(5)-gamma(3) GABA(A) receptor subunit gene cluster. GABAergic dysfunction has been hypothesized to contribute to the occurrence of epilepsy and cognitive and behavioral impairments in this condition. In the present study, analysis of GABA(A) receptor subunit expression and pharmacology was performed in cerebral cortex from four subjects with Angelman syndrome and compared to that from control tissue. The membrane fraction of frozen postmortem neocortical tissue was isolated and subjected to quantitative Western blot analysis. The ratios of beta(3)/beta(2) and alpha(5)/alpha(1) subunit protein expression in Angelman syndrome cortex were significantly decreased when compared with controls. An additional membrane fraction was injected into Xenopus oocytes, resulting in incorporation of the brain membrane vesicles with their associated receptors into the oocyte cellular membrane. Two-electrode voltage-clamp analysis of GABA(A) receptor currents was then performed. Studies of GABA(A) receptor pharmacology in Angelman syndrome cortex revealed increased current enhancement by the alpha(1)-selective benzodiazepine-site agonist zolpidem and by the barbiturate phenobarbital, while sensitivity to current inhibition by zinc was decreased. GABA(A) receptor affinity and modulation by neurosteroids were unchanged. This shift in GABA(A) receptor subunit expression and pharmacology in Angelman syndrome is consistent with impaired extrasynaptic but intact to augmented synaptic cortical GABAergic inhibition, which could contribute to the epileptic, behavioral, and cognitive phenotypes of the disorder.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
1872-7972
pubmed:author
pubmed:copyrightInfo
2010 Elsevier Ireland Ltd. All rights reserved.
pubmed:issnType
Electronic
pubmed:day
15
pubmed:volume
483
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
167-72
pubmed:meshHeading
pubmed-meshheading:20692323-Adolescent, pubmed-meshheading:20692323-Adult, pubmed-meshheading:20692323-Angelman Syndrome, pubmed-meshheading:20692323-Animals, pubmed-meshheading:20692323-Case-Control Studies, pubmed-meshheading:20692323-Cerebral Cortex, pubmed-meshheading:20692323-Child, Preschool, pubmed-meshheading:20692323-Dose-Response Relationship, Drug, pubmed-meshheading:20692323-Female, pubmed-meshheading:20692323-GABA Modulators, pubmed-meshheading:20692323-Gene Expression Regulation, pubmed-meshheading:20692323-Humans, pubmed-meshheading:20692323-Male, pubmed-meshheading:20692323-Membrane Potentials, pubmed-meshheading:20692323-Oocytes, pubmed-meshheading:20692323-Patch-Clamp Techniques, pubmed-meshheading:20692323-Phenobarbital, pubmed-meshheading:20692323-Protein Subunits, pubmed-meshheading:20692323-Receptors, GABA, pubmed-meshheading:20692323-Xenopus, pubmed-meshheading:20692323-gamma-Aminobutyric Acid
pubmed:year
2010
pubmed:articleTitle
Altered GABA(A) receptor subunit expression and pharmacology in human Angelman syndrome cortex.
pubmed:affiliation
Seattle Children's Research Institute, Center for Integrative Brain Research, Seattle, WA 98101, USA.
pubmed:publicationType
Journal Article