Psychology
Michael Morgan
In Search of the Neural Basis for Morphine Tolerance
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Dr. Michael Morgan’s research focuses on the body’s natural ability to modulate pain. This includes a reduction in pain following administration of opiates such as morphine and an increase in pain as occurs with the onset of fever. Dr. Morgan’s research examines the contribution of a midbrain structure called the periaqueductal gray (PAG) in these effects.
The administration of morphine or other opiates produce analgesia, in part, by binding to neurons in the PAG. Unfortunately, opiates lose their effectiveness with repeated administration because of the development of tolerance. In 1999, Dr. Morgan and colleagues published a manuscript showing that tolerance is caused by a change in the ventrolateral, but not the lateral part of the PAG in the rat. This finding set them on a search to identify the molecular changes underlying the development of tolerance in the ventrolateral PAG.
The search for the neural basis of tolerance to morphine led Dr. Morgan to collaborate with Dr. Susan Ingram, an expert in recording from neurons in brain slices. Through this collaboration, the researchers will work on trying to reveal how the molecular changes within a neuron are linked to the behavioral changes produced by morphine tolerance. This research is funded by the National Institute on Drug Abuse.
A 2002 report shows that 57 percent of adults in the U.S. experience chronic or recurrent pain [back pain (28 percent), arthritis/joint pain (19 percent), headaches/migraines (17 percent), knee pain (17 percent)]. Forty-two percent of these chronic pain suffers are not satisfied with the treatment for their pain. Given that opiates are the most potent analgesics available, Dr. Morgan hopes that by uncovering the neural mechanisms underlying tolerance to opiates, the molecular mechanism underlying tolerance can be blocked, enhancing the analgesic effects of the opiates.
Contact Information
Mike Morgan, Ph.D.
Associate Professor
Psychology
Washington State University Vancouver
14204 NE Salmon Creek Ave.
Vancouver, WA 98686-9600
Telephone: 360-546-9726
E-Mail: morgan@vancouver.wsu.edu |
