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CSUB Professor & students to present research
November 9, 2005
CONTACT: Mike Stepanovich, 661/654-2456,,
or Jaclyn Loveless, 661/654-2138,

A California State University, Bakersfield professor along with two graduate students will be presenting their research at the 35th annual Society for Neuroscience meeting Nov. 12 – 16 in Washington, D.C. where thousands are expected to attend.

Isabel Sumaya, CSUB psychology professor, along with her students Dee Bailey, a psychology graduate student, and Patrick Grijalva, an interdisciplinary studies graduate student, will present their research on the interaction between a high fat diet and the antidepressant Prozac in rats. Their work was chosen out of 17,000 studies to highlight during the meeting later this week.

Bailey said the study was undertaken based on previous reports that a caloric restriction of a high fat diet altered the rat serotonin system, a brain chemical that has been linked to depression. But how can the researchers test lab rats for depression? “In humans, one of the symptoms of depression is learned helplessness. You’ll see this in humans that are clinical depressed. They’ll just give up on many things that they normally cared about in their life,” Sumaya explained. “As animal researchers, we develop paradigms that induce at least one symptom of the disorder found in humans. In the case of animal models of depression, that’s what we test the rats for, learned helplessness.”

Bailey, Grijalva and Sumaya have taken a group of rats and given them a diet made of 32.5 percent fat. Normal rat chow contains about 11 percent fat. In their study they gave some rats all they could eat of this high fat diet while others were restricted on how much they could eat during either a seven day period or a 30 day period. They then gave some rats Prozac before testing them in a six-minute forced swim test. This is where the rats are individually placed in cylinders of water and the researchers observe changes and length time in the rats’ efforts to escape. “A normal rat realizes during the first two minutes of the test that they can’t get out,” she explained. “They’ll ultimately give up and just float. This animal will undergo learned helplessness.”

The researchers discovered the rats that where allowed to eat as much as they wanted of the high fat diet and given Prozac had a significant increase in their immobility compared to the rats put on a restricted amount and therefore “displayed more of the depressive-like symptom of learned helplessness.” Sumaya said, “This effect was found to be greater in the group put on the diet for seven days as compared to 30 days, which is very interesting. The effect of the diet appears to be rapid.”

She did add their research is preliminary and requires further study. Sumaya said they were not expecting these results and have much to think about in the possible biochemical explanations for the results. “If we were to make the huge leap from the basic research we have done here to human populations, these data may have implications for humans taking Prozac and their intake of fat,” she said.

The students are thrilled to be a part of the research. “It’s truly a creative process,” Bailey said. “It’s a great opportunity and lots of fun. It’s why I show up everyday.”

Grijalva echoed Bailey. “This has been really great for me,” he said. “Dr. Sumaya has taken me under her wing and inspired me to go branch off and do my own research.”

The Research Council of the University (RCU), as well as the Student Research Scholars program (SRS) at CSUB has fully funded the study. Sumaya said, “There is so much more we need to do to follow up on these important findings. Although we as humans can very cheaply get our high fat diet complements of the fast-food industry, the cost to have rat chow specially formulated with a high fat content costs our lab thousands of dollars.” Sumaya is currently working on getting additional funding for the project.

For additional information, please contact Sumaya at (661) 654-2381.



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