Villumsen, IS;
Wellendorph, P;
Smart, TG;
(2015)
Pharmacological characterisation of murine α4β1δ GABAA receptors expressed in Xenopus oocytes.
BMC Neuroscience
, 16
, Article 8. 10.1186/s12868-015-0148-4.
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Abstract
BACKGROUND: GABAA receptor subunit composition has a profound effect on the receptor's physiological and pharmacological properties. The receptor β subunit is widely recognised for its importance in receptor assembly, trafficking and post-translational modifications, but its influence on extrasynaptic GABAA receptor function is less well understood. Here, we examine the pharmacological properties of a potentially native extrasynaptic GABAA receptor that incorporates the β1 subunit, specifically composed of α4β1δ and α4β1 subunits. RESULTS: GABA activated concentration-dependent responses at α4β1δ and α4β1 receptors with EC50 values in the nanomolar to micromolar range, respectively. The divalent cations Zn(2+) and Cu(2+), and the β1-selective inhibitor salicylidine salicylhydrazide (SCS), inhibited GABA-activated currents at α4β1δ receptors. Surprisingly the α4β1 receptor demonstrated biphasic sensitivity to Zn(2+) inhibition that may reflect variable subunit stoichiometries with differing sensitivity to Zn(2+). The neurosteroid tetrahydro-deoxycorticosterone (THDOC) significantly increased GABA-initiated responses in concentrations above 30 nM for α4β1δ receptors. CONCLUSIONS: With this study we report the first pharmacological characterisation of various GABAA receptor ligands acting at murine α4β1δ GABAA receptors, thereby improving our understanding of the molecular pharmacology of this receptor isoform. This study highlights some notable differences in the pharmacology of murine and human α4β1δ receptors. We consider the likelihood that the α4β1δ receptor may play a role as an extrasynaptic GABAA receptor in the nervous system.
| Type: | Article |
|---|---|
| Title: | Pharmacological characterisation of murine α4β1δ GABAA receptors expressed in Xenopus oocytes |
| Location: | England |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1186/s12868-015-0148-4 |
| Publisher version: | http://dx.doi.org/10.1186/s12868-015-0148-4 |
| Language: | English |
| Additional information: | Copyright © Villumsen et al.; licensee BioMed Central. 2015. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. |
| Keywords: | Animals, Cations, Divalent, Copper, Desoxycorticosterone, Dose-Response Relationship, Drug, GABA-A Receptor Agonists, GABA-A Receptor Antagonists, Mice, Oocytes, Patch-Clamp Techniques, Rats, Receptors, GABA-A, Xenopus laevis, Zinc, gamma-Aminobutyric Acid |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Life Sciences UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Life Sciences > Div of Biosciences UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Life Sciences > Div of Biosciences > Neuro, Physiology and Pharmacology |
| URI: | https://discovery.ucl.ac.uk/id/eprint/1492480 |
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