Role of intracellular Ca2+ signaling in the antinociceptive and discriminative stimulus effects of the imidazoline I2 receptor agonist 2-BFI in rats.

These results indicate that the antinociceptive effects of 2-BFI involve intracellular Ca2+ elevation and/or downstream Ca2+/calmodulin signaling, whereas the discriminative stimulus effects of 2-BFI are mediated by a distinct, independent mechanism.