A novel animal model of clinical depression devised by a University of Mississippi research psychologist shows promise for better diagnosis and treatment of the syndrome and may result in a technology patent for the university.
“There is certainly room for improvement across the board in treating those who suffer from clinical depression. Researchers are beginning to identify new areas in the brain that we need to target for better drug therapy treatment,” said the researcher Ken Sufka, UM professor of psychology and pharmacology.
Sufka is also a research scientist at the National Center for Natural Products Research, a unit of the UM School of Pharmacy. He has been studying the connection between anxiety and depression for several years, seeking ways to better diagnose and treat clinical depression. Besides developing a novel animal model of this clinical syndrome, Sufka’s study suggests that anxiety may be a prelude to a depressive disorder. His research includes work with socially raised chicks, which were monitored in observation chambers and the frequency of their vocalizations automatically tallied.
Allan Kalueff, a research fellow at Finland’s University of Tampere Medical School, said single-disorder models have dominated experimental neuroscience for years, which is at odds with the actual complexity of clinical phenotypes. To alleviate this deficit, Kalueff said the field clearly needs new approaches for mimicking the anxiety-depression pathogenesis.
“A novel model from Dr. Sufka and his colleagues not only addresses this need but also condenses the anxiety-depression continuum into a short testing period,” Kalueff said. “Representing an important methodological advance, this model is highly congruent with newly appreciated concepts of commonality between stress-related brain disorders.”
Sufka explained that during the initial five to 10 minutes of separation, the chicks chirp loudly, displaying anxiety as they call out to their social companions. After 20 to 30 minutes, the chirping diminished by about half as the chicks entered what appeared to be a state of depression.
“More importantly, we have shown the model to be extremely sensitive to anti-anxiety and antidepressant drugs,” Sufka said. “We were the first laboratory to describe the anxiety-depression continuum in fowl chicks,” he said. “By using chicks, it’s a cost-efficient alternative to the more expensive rodent model; further, we can conduct two drug screenings in one experiment.”
Walter Chambliss, UM director of technology management in the Office of Research and Sponsored Programs, said his team is working to help secure future research opportunities.
“The university has filed a patent to protect this novel drug discovery method,” Chambliss said. “We are actively seeking one or more licensing partners within the pharmaceutical industry to commercialize the patent-pending technology.”
In the December 2006 issue of the peer-reviewed journal Behavioural Pharmacology, Sufka presents his novel anxiety-depression continuum model and argues against the conventional belief that anxiety and depression are separate clinical syndromes.
In a follow-up article, soon to be published in the Journal of Psychopharmacology, Sufka demonstrates the pharmacological sensitivity of the chick model as a potential drug screening test.
“The old school view is that anxiety and depression are separate clinical syndromes and not at all related,” Sufka said. “New research tells us this is wrong, and now we need to reconceptualize our way of approaching and dealing with these related mental health conditions.”
Sufka said he believes the new animal model can be used in research to better understand the brain events that occur during anxiety and depression, as well as to search for changes in the brain system that help identify targets for drug development.
Sufka’s research team consisted of former UM health and exercise science professor Edmund Acevedo and four former UM students, including three doctoral students and a Sally McDonnell Barksdale Honors College student. Funding for the work has come solely from on-campus sources.
“This work represents the most recent culmination of a careful and programmatic line of research done over the years by Dr. Sufka and his colleagues on distress vocalizations in chicks,” said UM psychology chair Michael Allen. “This careful progression of studies serves as an exemplar for how good research can be done.”
The team is conducting validation studies, including the testing of approximately 12 new drugs that show promise in treating depression, Sufka said.
“Our next step is to examine changes in brain chemistry that parallel the presentation of the anxiety and depression phases,” Sufka said. “We hope these brain changes will offer clues to new targets in the development of novel antidepressant drugs.”