Purchase this article with an account.
P. de la Villa, N. Cardinale, L. Rivera; GABAA Receptors in Retinal Horizontal Cells: Single Channel Conductance and Pharmacological Properties. Invest. Ophthalmol. Vis. Sci. 2009;50(13):1036.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
As al attempt to deep study retinal functional mechanisms, we have performed a series of experiments in order to fully characterize the ionic currents induced by gamma-aminobutiric acid (GABA) in horizontal cells of the mammalian retina.
For such purpose we have used axonless horizontal cells enzymatically dissociated form the rabbit retina. We have recorded from a total of 85 isolated cells, by the use of the patch clamp technique in the whole-cell voltage clamp configuration.
Local application of GABA on the cell surface, either by super fusion or puff - pressure, induces a chloride mediated current in horizontal cells. Ionic currents induced by GABA were completely and reversibly blocked by biccuculine, thus indicating the GABAA nature of the receptor expressed in mammalian horizontal cells. In a series of experiments, we characterized the GABA sensitivity and the degree of desensitization. Noise analysis allowed us to estimate the single channel conductance of the GABAA receptors. An estimation of the number of channels expressed by axonless horizontal cells was estimated as well. GABA induced currents were also studied from a pharmacological point of view. A comparative study between the effect of barbiturates and benzodiacepines on GABAA receptors was performed on horizontal cells.
We conclude that horizontal cells of the mammalian retina express GABAA receptors whose channel properties have been now fully characterized in terms of single channel conductance, pharmacology and kinetics.
This PDF is available to Subscribers Only