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Reversible modulation of GABA A receptor‐mediated currents by light is dependent on the redox state of the receptor
Author(s) -
Leszkiewicz Daniel N.,
Aizenman Elias
Publication year - 2003
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1046/j.1460-9568.2003.02656.x
Subject(s) - gabaa receptor , glycine receptor , biophysics , receptor , gabaa rho receptor , chemistry , population , long term potentiation , neuroscience , gaba receptor antagonist , biology , biochemistry , glycine , bicuculline , medicine , environmental health , amino acid
Light has recently been shown to be a physical modulator of GABA A receptor activity. Here, we further characterize the effects of light on a native cortical and retinal population of GABA A receptors, and identify a possible mechanism for light induced potentiation using recombinant receptors. GABA‐induced currents in cortical neurons were observed to be rapidly and reversibly potentiated following exposure to a brief flash of light (0.5–2 s; > 280 nm) directed via an optical fibre (50 µm i.d.). GABA A receptor‐mediated responses in retinal ganglion cells were also enhanced by light, while glycine‐induced currents in these cells were unaffected by the same stimulus. We also determined that physiological levels of light, that is, those that would normally reach the retina, also enhanced GABA‐induced currents. Finally, we observed that chemical reduction of recombinant α 1 β 2 and α 1 β 2 γ 2S GABA A receptors by dithiothreitol substantially attenuated the effects of light. These results suggest that GABA A receptors can be reversibly modified by a brief pulse of light via an allosteric mechanism that is intimately linked to redox modulation.