Julian Pittman, an associate professor in the department of biological and environmental sciences, has been quoted in The New York Times for his research on anxiety and depression in fish.
Zebrafish, a species of small freshwater fish, can provide insight on the human mental experience and how to treat mental illness, according to the National Center for Biotechnology Information (NCBI) and the U.S. National Library of Medicine.
Pittman uses zebrafish as a model for his investigation, and he said he is trying to link “the neural mechanisms behind that (anxiety and depression) and discover new antidepressants.”
Pittman and his team induced depression in the fish by giving them a continuous supply of ethanol, a chemical found in alcoholic drinks, to make the fish drunk.
Then, the supply was cut off, which forced the fish into depression.
After giving the fish antidepressant treatment, the fish could recover within two weeks.
“(Zebrafish) are a good model organism and exhibit the same behavioral symptoms humans do,” Pittman told the Tropolitan. “We perform a novel tank diving test, and we measure the amount of time they spend above or below a line in the tank.”
The novel tank test is conducted when the fish are placed in a novel area, in this case the tank, and assessed based on its movement within the tank, according to NCBI.
Pittman said that if a fish hangs toward the bottom of the tank five minutes after being dropped in, then it is depressed. If the fish stays near the top, then it is not depressed.
Depending on how much time the zebrafish spends at one level of the tank, Pittman can measure the level of depression, how to treat the fish and how effective the antidepressant might be.
Pittman’s research can help develop new medicine for depression, and according to the NCBI, his efforts are supported by other findings. The zebrafish “has emerged as a model species for translational research in various neuroscience areas, including depressive disorders,” according to the NCBI.
Establishing zebrafish as a model is a big step for Pittman’s research, but he still has a long way to go.
“It’s an ongoing process,” Pittman said. “The concentration of those neurotransmitters and the kinds of neurotransmitters are similar, but we don’t know if the projections and the dynamics of those projections are similar.”
The NCBI confirms that the physiology of zebrafish is similar to mammals’. Zebrafish are sensitive to common psychotropic drugs (“psychiatric medicines that alter chemical levels in the brain which impact mood and behavior,” according to ABC News) and exhibit similar behaviors to humans.
When zebrafish become depressed, they mimic human depression, losing interest in everyday activities like eating or exploring.
In an interview with The New York Times, Victoria Braithwaite, a professor of fisheries and biology at Penn State, said that depression in fish is mostly caused by boredom.
“Fish are naturally curious and seek novel things out,” Braithwaite said.
Braithwaite said to reduce fish boredom, moving plants and decorations around or putting new ones in the tank so the fish can stay stimulated can help.
By analyzing anxiety and depression in zebrafish, Pittman’s study may lead to better and more therapeutic understanding and treatment of anxiety and depression in humans.
The New York Times article quoting Pittman was published Oct. 16, 2017, and focuses on depression in fish and new research methods for testing this phenomenon.