GABA receptor subunits in human auditory cortex in normal and stroke cases.
GABA receptors are ubiquitous in the cerebral cortex and play a major role in shaping responses of cortical neurons. GABA(A) and GABA(B) receptor subunit expression was visualized by immunohistochemistry in human auditory areas from both hemispheres in 9 normal subjects (aged 43-85 years; time between death and fixation 6-24 hours) and in 4 stroke patients (aged 59-87 years; time between death and fixation 7-24 hours) and analyzed qualitatively for GABA(A) and semiquantitatively for GABA(B) receptor subunits. In normal brains, the primary auditory area (TC) and the surrounding areas TB and TA displayed distinct GABA(A) receptor subunit labeling with differences among cortical layers and areas. In postacute and chronic stroke we found a layer-selective downregulation of the alpha-2 subunit in the anatomically intact cerebral cortex of the intact and of the lesioned hemisphere, whereas the alpha-1, alpha-3 and beta-2/3 subunits maintained normal levels of expression. The GABA(B) receptors had a distinct laminar pattern in auditory areas and minor differences among areas. Unlike in other pathologies, there is no modulation of the GABA(B) receptor expression in subacute or chronic stroke.
Sacco
Carolyn B
CB
Neuropsychology and Neurorehabilitation Service, Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland.
Tardif
Eric
E
Genoud
Christel
C
Probst
Alphonse
A
Tolnay
Markus
M
Janzer
Robert-Charles
RC
Verney
Catherine
C
Kraftsik
Rudolf
R
Clarke
Stephanie
S
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001303:Auditory Cortex / Q000378:metabolism* / Q000473:pathology / Q000648:ultrastructure; D015536:Down-Regulation / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D046529:Microscopy, Electron, Transmission / Q000379:methods; D016253:Microscopy, Immunoelectron; D008875:Middle Aged; D011180:Postmortem Changes; D021122:Protein Subunits / Q000378:metabolism*; D011963:Receptors, GABA-A / Q000378:metabolism*; D020521:Stroke / Q000473:pathology*
D021122:Protein Subunits; D011963:Receptors, GABA-A