P.W. and P.S. contributed equally to the study.
Cellular localization and function of DARPP-32 in the rodent retina
Version of Record online: 6 JUN 2007
European Journal of Neuroscience
Volume 25, Issue 11, pages 3233–3242, June 2007
How to Cite
Witkovsky, P., Svenningsson, P., Yan, L., Bateup, H. and Silver, R. (2007), Cellular localization and function of DARPP-32 in the rodent retina. European Journal of Neuroscience, 25: 3233–3242. doi: 10.1111/j.1460-9568.2007.05571.x
- Issue online: 6 JUN 2007
- Version of Record online: 6 JUN 2007
- Received 28 May 2006, revised 30 March 2007, accepted 2 April 2007
- D1 dopamine receptor;
The goal of the present study was to elucidate the role of DARPP-32 (dopamine- and cyclic adenosine 3′-5′-monophosphate-regulated phosphoprotein, 32 kDa) in retinal function. We examined mouse and rat retinas for the presence of DARPP-32 by immunocytochemistry. In both rodent retinas DARPP-32 immunoreactivity was localized to horizontal and AII amacrine neurons and to the Mueller glial cells, using immuno-double labelling. Additional unidentified neurons in the amacrine cell layer also showed DARPP-32 immunoreactivity. Using mice entrained to a 12–12 h light–dark cycle, we found that exposure to light presented during the dark phase significantly enhanced phosphorylation of DARPP-32 at threonine (Thr) 34 and phosphorylation of the ionotropic glutamate receptor subunit GluR1 at serine (Ser) 845, as measured by immunoblots. However, light also increased Ser 845-GluR1 phosphorylation in DARPP-32-knockout mice. When a dopamine D1 receptor antagonist was injected into the eye prior to light exposure, phosphorylation of both Thr 34-DARPP-32 and Ser 845-GluR1 was significantly reduced. These data indicate that DARPP-32 participates in dopamine-mediated modifications of retinal function. We also tested for a possible circadian rhythm of Thr 34- and Thr 75-DARPP-32 and Ser 845-GluR1 expression. No significant circadian rhythm of either DARPP-32 or GluR1 phosphorylation was found.