Molecular Neurobiology

, Volume 18, Issue 1, pp 35–86

The diversity of GABAA receptors

Pharmacological and electrophysiological properties of GABAA channel subtypes

Authors

  • Wulf Hevers
    • Wulf Hevers & Hartmut Lüddens Clinical Research Group, Department of PsychiatryUniversity of Mainz
  • Hartmut Lüddens
    • Wulf Hevers & Hartmut Lüddens Clinical Research Group, Department of PsychiatryUniversity of Mainz
Article

DOI: 10.1007/BF02741459

Cite this article as:
Hevers, W. & Lüddens, H. Mol Neurobiol (1998) 18: 35. doi:10.1007/BF02741459

Abstract

The amino acid γ-aminobutyric-acid (GABA) prevails in the CNS as an inhibitory neurotrans-mitter that mediates most of its effects through fast GABA-gated Cl-channels (GABAAR). Molecular biology uncovered the complex subunit architecture of this receptor channel, in which a pentameric assembly derived from five of at least 17 mammalian subunits, grouped in the six classes α, β, γ, δ, ε, and ρ, permits a vast number of putative receptor isoforms. The subunit composition of a particular receptor determines the specific effects of allosterical modulators of the GABAARs like benzodiazepines (BZs), barbiturates, steroids, some convulsants, polyvalent cations, and ethanol. To understand the physiology and diversity of GABAARs, the native isoforms have to be identified by their localization in the brain and by their pharmacology. In heterologous expression systems, channels require the presence of α, β, and γ subunits in order to mimic the full repertoire of native receptor responses to drugs, with the BZ pharmacology being determined by the particular α and γ subunit variants. Little is known about the functional properties of the β, δ, and ε subunit classes and only a few receptor subtype-specific substances like loreclezole and furosemide are known that enable the identification of defined receptor subtypes. We will summarize the pharmacology of putative receptor isoforms and emphasize the characteristics of functional channels. Knowledge of the complex pharmacology of GABAARs might eventually enable site-directed drug design to further our understanding of GABA-related disorders and of the complex interaction of excitatory and inhibitory mechanisms in neuronal processing.

Index Entries

GABAAbenzodiazepineselectrophysiologyrecombinant receptors

Copyright information

© Humana Press Inc 1998