GABAB receptor-mediated activation of astrocytes by gamma-hydroxybutyric acid

Timothy Gould, Lixin Chen, Zsuzsa Emri, Tiina Pirttimaki, Adam C. Errington, Vincenzo Crunelli, H. Rheinallt Parri

Research output: Article

14 Citations (Scopus)

Abstract

The gamma-aminobutyric acid (GABA) metabolite gamma-hydroxybutyric acid (GHB) shows a variety of behavioural effects when administered to ani and humans, including reward/addiction properties and absence seizures. At the cellular level, these actions of GHB are mediated by activation of neuronal GABAB receptors (GABABRs) where it acts as a weak agonist. Because astrocytes respond to endogenous and exogenously applied GABA by activation of both GABAA and GABABRs, here we investigated the action of GHB on astrocytes on the ventral tegmental area (VTA) and the ventrobasal (VB) thalamic nucleus, two brain areas involved in the reward and proepileptic action of GHB, respectively, and compared it with that of the potent GABABR agonist baclofen. We found that GHB and baclofen elicited dose-dependent (ED50: 1.6 mM and 1.3 mM, respectively) transient increases in intracellular Ca2þ in VTA and VB astrocytes of young mice and rats, which were accounted for by activation of their GABABRs and mediated by Ca2þ release from intracellular store release. In contrast, prolonged GHB and baclofen exposure caused a reduction in spontaneous astrocyte activity and glutamate release from VTA astrocytes. These findings have key (patho)physiological implications for our understanding of the addictive and proepileptic actions of GHB.

Original languageEnglish
JournalPhilosophical Transactions of the Royal Society B: Biological Sciences
Volume369
Issue number1654
DOIs
Publication statusPublished - okt. 19 2014

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ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Agricultural and Biological Sciences(all)

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