Loss of functional GABA A receptors in the Alzheimer diseased brain

Agenor Limon-Ruiz, Jorge Mauricio Reyes-Ruiz, Ricardo Miledi

Research output: Contribution to journalArticle

111 Citations (Scopus)

Abstract

The cholinergic and glutamatergic neurotransmission systems are known to be severely disrupted in Alzheimer's disease (AD). GABAergic neurotransmission, in contrast, is generally thought to be well preserved. Evidence from animal models and human postmortem tissue suggest GABAergic remodeling in the AD brain. Nevertheless, there is no information on changes, if any, in the electrophysiological properties of human native GABA receptors as a consequence of AD. To gain such information, we have microtransplanted cell membranes, isolated from temporal cortices of control and AD brains, into Xenopus oocytes, and recorded the electrophysiological activity of the transplanted GABA receptors. We found an age-dependent reduction of GABA currents in the AD brain. This reduction was larger when the AD membranes were obtained from younger subjects. We also found that GABA currents fromAD brains have a faster rate of desensitization than those from non-AD brains. Furthermore, GABA receptors from AD brains were slightly, but significantly, less sensitive to GABA than receptors from non-AD brains. The reduction of GABA currents in AD was associated with reductions of mRNA and protein of the principal GABA receptor subunits normally present in the temporal cortex. Pairwise analysis of the transcripts within control and AD groups and analyses of the proportion of GABA receptor subunits revealed down-regulation of α1 and γ2 subunits in AD. In contrast, the proportions of α2, β1, and gamma;1 transcripts were up-regulated in the AD brains. Our data support a functional remodeling of GABAergic neurotransmission in the human AD brain.

Original languageEnglish (US)
Pages (from-to)10071-10076
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume109
Issue number25
DOIs
StatePublished - Jun 19 2012
Externally publishedYes

Fingerprint

GABA-A Receptors
Alzheimer Disease
GABA Receptors
Brain
Synaptic Transmission
gamma-Aminobutyric Acid
Brain Diseases
Temporal Lobe
Xenopus
Cholinergic Agents
Oocytes
Down-Regulation
Animal Models
Cell Membrane

Keywords

  • Gephyrin
  • Glutamate receptor
  • Neurodegeneration
  • Synaptic mechanism

ASJC Scopus subject areas

  • General

Cite this

Loss of functional GABA A receptors in the Alzheimer diseased brain. / Limon-Ruiz, Agenor; Reyes-Ruiz, Jorge Mauricio; Miledi, Ricardo.

In: Proceedings of the National Academy of Sciences of the United States of America, Vol. 109, No. 25, 19.06.2012, p. 10071-10076.

Research output: Contribution to journalArticle

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