Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.


Sci. STKE, 14 January 2003
Vol. 2003, Issue 165, p. pe2
[DOI: 10.1126/stke.2003.165.pe2]


DARPP Chocolate: A Caffeinated Morsel of Striatal Signaling

Elena Bastia and Michael A. Schwarzschild*

Center for Aging, Genetics and Neurodegeneration, Department of Neurology, Massachusetts General Hospital, Boston, MA 02129, USA.

Abstract: The psychomotor stimulant effects of caffeine, the most widely consumed psychoactive substance, are mediated through its antagonism of extracellular adenosine receptors in the basal ganglia. In the absence of caffeine, adenosine stimulates inhibitory striatopallidal neurons that suppress motor activity by binding to A2A receptors, thereby activating a cyclic adenosine 3',5'-monophosphate (cAMP) and protein kinase A signaling pathway. Bastia and Schwarzschild discuss recent research implicating DARRP-32 (dopamine- and cAMP-regulated phosphoprotein of 32 kilodaltons) as an attractive mediator of the sustained psychomotor stimulant effect seen with low doses of caffeine. They highlight the role of postsynaptic A2A receptor blockade, but leave open the possibility that antagonism of presynaptic or postsynaptic A1 receptors also contributes to DARPP-32-dependent psychomotor stimulation by caffeine.

*Corresponding author. E-mail: MichaelS{at}

Citation: E. Bastia, M. A. Schwarzschild, DARPP Chocolate: A Caffeinated Morsel of Striatal Signaling. Sci. STKE 2003, pe2 (2003).

Read the Full Text

To Advertise     Find Products

Science Signaling. ISSN 1937-9145 (online), 1945-0877 (print). Pre-2008: Science's STKE. ISSN 1525-8882