Duttaroy, A.; Gomea, J.; Gan, J.; Basile, A. S.; Harman, W. D.; Smith, P. L.; Felder, C. C.; Levey, A. I.; Wess, J. Evaluation of Muscarinic Agonist-Induced Analgesia in Muscarinic Acetylcholine Receptor Knockout Mice. J. Mol. Pharmacol. 2002, 62, 1084.