Sept. 30, 1996 -- Research on the brain of a small amphibian is shedding new light about a debilitating and tragic disease in humans, according to a University of Wyoming scientist.
Jim Rose, a professor in the UW Department of Psychology, is studying hormones in small amphibious newts that could improve our understanding of human brain activity, possibly leading to new ways for treating such ailments as nervous system injury, depression or Alzheimer's disease. His work is related to a corresponding line of investigation by Frank Moore at Oregon State University.
"Moore has found that stressors, such as immobilization or temperature stresses of these amphibians, result in a corticosterone secretion," Rose says. "Secretion of this hormone acts rapidly on brain cells and interferes in the newt's functioning in such a way that reproductive behavior is specifically blocked. My part of the project is to identify this hormone's effect on neurons in the brain by seeing how the circuitry is disrupted and correspondingly how reproductive behavior is blocked."
Rose says research on the newts has implications for humans.
"It's been suspected for a long time that the human hormone, cortisol, which is similar to the corticosterone we study in the newts, can have a very rapid effect on brain cells," he says. "It has been demonstrated that many people with Alzheimer's disease are secreting high levels of cortisol. Stress hormones of this type, when they are secreted at a high level, can cause brain degeneration. The very same parts of the brain that degenerate in response to cortisol are the same areas most affected in Alzheimer's disease."
Rose says researchers hope to develop a drug that will block the destructive action of cortisol. The key to doing that may be to distinguish the action of hormones on the cell membrane from the action of hormones on the cell nucleus in newts.
"For example, this rapid affect of the hormone that we've been studying in the newt is due to a particular molecule in the cell membrane of brain cells," he says. "We don't know much about the structure of that molecule but it might be possible to design another hormone-like compound that could bind with that molecule and block the effect of the natural hormone with a kind of competitive interaction. That is one possible therapeutic strategy."
The newts also are the subject of another study directed by Rose, conducted by UW psychology senior Glenn Marrs. He is investigating the effects of corticosterone on the recovery of movement control following spinal cord injury. Support for this study is provided by a National Science Foundation (NSF) grant to Rose and an NSF fellowship to Marrs.
Rose says both studies have implications for helping Alzheimer's patients or people with traumatic neural injury because it may be possible to produce synthetic hormones that target the cells you want to protect. That way, people are treated by the drug's beneficial effects without suffering from its pathological side effects.
"If you understand better how to distinguish the effects we don't want on the brain from those we do want, you can design drugs with more selective action," Rose says.
For more information, call Rose at (307) 766-6719.