Ne through stimulation of adenosine A2A receptors in a A2A-D2 heterodimer (Ferre et al., 1991). These effects can be seen in functional studies as well. Thus, the agonist effects of orexin-A can be reversed by the cannabinoid receptor CB1 inverse agonist SR141716A through formation of an orexin-1/CB1 receptor heterodimer (Hilairet et al., 2003). Conformational changes in dimers open the possibilit