Expression of GABAρ receptors in the neostriatum: localization in aspiny, medium spiny neurons and GFAP-positive cells
Version of Record online: 23 JAN 2012
© 2011 The Authors. Journal of Neurochemistry © 2011 International Society for Neurochemistry
Journal of Neurochemistry
Volume 122, Issue 5, pages 900–910, September 2012
How to Cite
Rosas-Arellano, A., Machuca-Parra, A. I., Reyes-Haro, D., Miledi, R. and Martínez-Torres, A. (2012), Expression of GABAρ receptors in the neostriatum: localization in aspiny, medium spiny neurons and GFAP-positive cells. Journal of Neurochemistry, 122: 900–910. doi: 10.1111/j.1471-4159.2011.07621.x
- Issue online: 20 AUG 2012
- Version of Record online: 23 JAN 2012
- Accepted manuscript online: 13 DEC 2011 11:27AM EST
- Received March 21, 2011; revised manuscript received November 22, 2011; accepted December 2, 2011.
- medium spiny neurons;
J. Neurochem. (2012) 122, 900–910.
GABAergic transmission in the neostriatum plays a central role in motor coordination, in which a plethora of GABA-A receptor subunits combine to modulate neural inhibition. GABAρ receptors were originally described in the mammalian retina. These receptors possess special electrophysiological and pharmacological properties, forming a characteristic class of ionotropic receptors. In previous studies, we suggested that GABAρ receptors are expressed in the neostriatum, and in this report we show that they are indeed present in all the calretinin-positive interneurons of the neostriatum. In addition, they are located in calbindin-positive interneurons and projection neurons that express the dopamine D2 receptor. GABAρ receptors were also located in 30% of the glial fibrillary acidic protein-positive cells, and may therefore also contribute to gliotransmission. Quantitative reverse transcription-PCR suggested that the mRNAs of this receptor do not express as much as in the retina, and that GABAρ2 is more abundant than GABAρ1. Electrophysiological recordings in brain slices provided evidence of neurons expressing a cis-4-aminocrotonic acid-activated, 1,2,5,6-tetrahydropyridine-4-yl methylphosphinic acid-sensitive ionotropic GABA receptor, indicating the presence of functional GABAρ receptors in the neostriatum. Finally, electron-microscopy and immunogold located the receptors mainly in perisynaptic as well as in extrasynaptic sites. All these observations reinforce the importance of GABAρ receptors in the neostriatum and contribute to the diversity of inhibitory regulation in this area.