Professor of AnesthesiologyChronic pain is a major public health problem. Chronic, pathologic pain states affect one-fourth of the population. A significant number of patients with pain syndromes, particularly those with chronic, abnormal pains, continue to suffer despite attempts at treatment. The lack of effective clinical treatments results in a national loss of productivity, personal and family suffering, depression and suicide.
Our laboratory focuses on the study of neuropathic pain, a particularly complex chronic pain resulting from injury or disease of nerves and a particularly difficult pain to treat. We utilize an experimental model of neuropathic pain created by surgical ligation of the L5 and L6 spinal nerves in rats. We are currently conducting two lines of research. We are studying the effectiveness of cannabinoid receptor agonists in reversing the signs of neuropathic pain. Second, we are studying the expression and function of selected neurotransmitters in the spinal cord following nerve injury. This research focuses on neuropeptides postulated to be important in the creation and maintenance of the pain state, particularly the neuropeptide, dynorphin.
Our work combines in vitro analytical and molecular techniques with in vivo measurements of pain sensitivity. Although we primarily focus on the spinal nerve ligation model, when appropriate we also study patients with neuropathic pain syndromes.
Malan TP, Ibrahim MM, Vanderah TW, Makriyannis A, Porreca F (2003) Inhibition of pain responses by activation of CB2 cannabinoid receptors. Chem Phys Lipids 121: 191 – 200.
Malan TP, Ibrahim MM, Vanderah TW, Makriyannis A, Porreca F (2003) CB2 cannabinoid receptor agonists: pain relief without psychoactive effects. Curr Opin Pharmacol 3: 1-6.
Quartilho A, Mata HP, Ibrahim MM, Vanderah TW, Porreca F, Makriyannis A, Malan TP (in press) Inhibition of inflammatory hyperalgesia by activation of peripheral CB2 cannabinoid receptors. Anesthesiology.
Ibrahim MM, Deng H, Zvonok A, Cockayne DA Kwan J, Mata HP, Vanderah TW, Lai J, Porreca F, Makriyannis A, Malan TP (in press) Activation of CB2 cannabinoid receptors by AM1241 inhibits experimental neuropathic pain: pain inhibition by receptors not found in the central nervous system. Proc Natl Acac Sci, USA.
Malan TP, Ossipov MH, Ibrahim M, Bian DI, Lai J, Porreca F (2000) Extraterritorial neuropathic pain correlates with multisegmental elevation of spinal dynorphin in nerve-injured rats. Pain 86:185-194.