Mice learn tasks that may help treat human psychiatric disorders

August 1, 2006
Mice learn tasks that may help treat human psychiatric disorders
Joseph Garner is part of an international research team using mice to help diagnose many human mental disorders, including autism. Garner is a Purdue University assistant professor of animal sciences. Credit: Purdue University photo/Tom Campbell

Mice that couldn't be dissuaded from the object of their attention by a piece of sweet, crunchy cereal may help researchers find new treatments and cures for human disorders like autism and Parkinson's disease.

For the first time, a psychiatric test for monitoring many human mental abnormalities has been adapted for use in mice, according to researchers at Purdue University, University of California-Davis and Justus-Liebig University in Giessen, Germany. The test involves the ability to switch attention from one task to another, a skill often impaired in people with autism and similar illnesses.

"Without a measure of cognitive deficit in mice that is relevant to such disorders in humans, research into new diagnostic methods, treatments and cures is severely hindered," said Joseph Garner, a Purdue assistant professor of animal sciences and the study's lead author. "The level of complexity at which we assess mouse behavior is often very rudimentary, and it just does not match up with subtleties of the cognitive deficits in human mental dysfunction or with the tools we use to study the mechanisms that underlie disorders in people."

Garner and his colleagues designed a task to measure a process called set shifting in which a focus on one object must be abandoned in favor of another object or task. This test long has been used to monitor brain processes involved in human psychiatric disorders and also has been tailored to a few other animals. However, researchers previously had not adapted it to the most-used of research mammals, the common laboratory mouse.

"Set shifting underlies our ability to use categories in day-to-day life and our ability to do many things including execute complex plans," Garner said.

Garner's team reports its findings in the journal Behavioural Brain Research, which is currently online.

Set shifting as an important neuropsychological skill applies to more human mental disorders than any other measure, Garner said. Mechanisms in the brain that enable people to shift their focus from one task to another also seem to be present in most other mammals and probably also in birds.

"Set shifting occurs when you've learned to pay attention to one thing and then need to concentrate on something different," he said. "For instance, I could ask you to name the suit on playing cards as I turn them over, and then I'd ask you to tell me the numbers on the next cards I turn over.

"But you might fail to tell me the numbers because you are continuing to pay attention to the previous set - the card suits. You've both learned to pay attention to the suits and that the numbers are irrelevant so you should ignore them."

Mice compose the majority of medical research animals, but since no test existed to monitor them for such skills as set shifting, their usefulness in studying autism, other similar diseases and traumatic brain injuries was limited, Garner said.

The Garner team's mice were tested in a maze with rewards of one-quarter of a piece of sweetened cereal hidden in two-inch diameter metal bowls. The scientists varied the material inside the bowls where the cereal piece was hidden and also varied the outer texture and smell of the bowls.

The rodents learned to find the cereal by using a cue such as the bowl's outer texture. After experience solving a number of tasks with this cue, the animals were given a new cue for finding the cereal, such as the bowl's smell.

"Like people performing a series of similar tasks over and over and then having to change their focus to a new problem, the mice continued to look for the bowl with the same outer texture to find the cereal," Garner said. "The more times they had used the bowl texture as a cue, the more difficult it was for the animals to change to the new food-finding cue."

Almost all people have a little difficulty set-shifting in a task like this, he said. However certain patient groups find it very difficult. Therefore, similar tests are used to measure brain function in people.

"The data collected in this study begin to solve the problem of not having a way of measuring these neurological mechanisms in mice," Garner said. "Previously we were not able to measure this fundamental disease process in autism, trichotillomania (hair pulling), obsessive-compulsive disorder, Parkinson's disease, schizophrenia, Tourette's syndrome, traumatic frontal brain lobe injury and a host of other human mental disorders for which set shifting is an important monitoring tool."

According to the Centers for Disease Control and Prevention (CDC), 3.4 per 1,000 children have autism or another autism spectrum disorder, making these disorders about as common as Type I juvenile diabetes. This rate is higher than for other childhood disabilities, including Down's syndrome, cancer, cerebral palsy, hearing loss and vision impairment.

Although the number of children diagnosed with autism has increased dramatically over the past 12 years, the upward spiral may be due to better, more widespread understanding and diagnosis of the mental impairment, CDC experts said. Trichotillomania, which affects 3.4 percent of women, and some other disorders are even more prevalent.

Source: Purdue University

Explore further: Antioxidants help treat skin-picking disorder in mice, researcher says

Related Stories

Antioxidants help treat skin-picking disorder in mice, researcher says

July 13, 2015
Two antioxidant supplements are effective in treating skin-picking disorder in mice, according to a study led by a Stanford University School of Medicine researcher.

Why are so many of us over-sensitive?

June 14, 2016
When a gentle glow feels like a spotlight and everyday sounds hurt your ears, life can gets anxious and painful. But, discovers Emma Young, there may be an upside to being highly sensitive.

Scientists discover cancer markers may be present early during human development

August 5, 2015
Researchers at the Virginia Bioinformatics Institute have uncovered a link between the genomes of cells originating in the neural crest and development of tumors—a discovery that could lead to new ways to diagnose and treat ...

New genetic test may change how brain cancer is treated, researchers say

August 20, 2014
(Medical Xpress)—Scientists at Virginia Tech's Virginia Bioinformatics Institute working with the Center for Cancer and Blood Disorders at Children's National Medical Center have found a new way to diagnose brain cancer ...

Researchers demonstrate gender identity is reflected in the brain, including transgenderism

August 23, 2016
Women and men often show marked differences as regards mental illnesses. In order to learn more about this phenomenon, a project supported by the Austrian Science Fund FWF explored how opposite-sex hormonal therapy applied ...

Recommended for you

Creation of synthetic horsepox virus could lead to more effective smallpox vaccine

January 19, 2018
UAlberta researchers created a new synthetic virus that could lead to the development of a more effective vaccine against smallpox. The discovery demonstrates how techniques based on the use of synthetic DNA can be used to ...

Researchers illustrate how muscle growth inhibitor is activated, could aid in treating ALS

January 19, 2018
Researchers at the University of Cincinnati (UC) College of Medicine are part of an international team that has identified how the inactive or latent form of GDF8, a signaling protein also known as myostatin responsible for ...

Novel genomic tools provide new insight into human immune system

January 19, 2018
When the body is under attack from pathogens, the immune system marshals a diverse collection of immune cells to work together in a tightly orchestrated process and defend the host against the intruders. For many decades, ...

Intensive behavior therapy no better than conventional support in treating teenagers with antisocial behavior

January 19, 2018
Research led by UCL has found that intensive and costly multisystemic therapy is no better than conventional therapy in treating teenagers with moderate to severe antisocial behaviour.

Investigators eye new target for treating movement disorders

January 19, 2018
Blocking a nerve-cell receptor in part of the brain that coordinates movement could improve the treatment of Parkinson's disease, dyskinesia and other movement disorders, researchers at Vanderbilt University have reported.

Women run faster after taking newly developed supplement, study finds

January 19, 2018
A new study found that women who took a specially prepared blend of minerals and nutrients for a month saw their 3-mile run times drop by almost a minute.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.