Researchers identify protein necessary for behavioral flexibility

May 24, 2012 in Medical research

Researchers have identified a protein necessary to maintain behavioral flexibility, which allows us to modify our behaviors to adjust to circumstances that are similar, but not identical, to previous experiences. Their findings, which appear in the journal Cell Reports, may offer new insights into addressing autism and schizophrenia—afflictions marked by impaired behavioral flexibility.

Our stored memories from previous experiences allow us to repeat certain tasks. For instance, after driving to a particular location, we recall the route the next time we make that trip. However, sometimes circumstances change—one road on the route is temporarily closed—and we need to make adjustments to reach our destination. Our behavioral flexibility allows us to make such changes and, then, successfully complete our task. It is driven, in part, by protein synthesis, which produces experience-dependent changes in neural function and behavior.

However, this process is impaired for many, preventing an adjustment in behavior when faced with different circumstances. In the Cell Reports study, the researchers sought to understand how protein synthesis is regulated during behavioral flexibility.

To do so, they focused on the kinase PERK, an enzyme that regulates protein synthesis. PERK is known to modify eIF2alpha, a factor that is required for proper protein synthesis. Their experiments involved comparing normal lab mice, which possessed the enzyme, with those that lacked it.

In their study, the mice were asked to navigate a water maze, which included elevating themselves onto a platform to get out of the water. Normal mice and those lacking PERK learned to complete this task.

However, in a second step, the researchers tested the mice's behavioral flexibility by moving the maze's platform to another location, thereby requiring them to respond to a change in the terrain. Here, the normal mice located the platform, but those lacking PERK were unable to do so or took significantly more time to complete the task.

A second experiment offered a different test of the role of PERK in aiding behavioral flexibility. In this measure, both normal and mutant mice heard an audible tone that was followed by a mild foot shock. At this stage, all of the mice developed a normal fear response—freezing at the tone in anticipation of the foot shock. However, the researchers subsequently removed the foot shock from the procedure and the mice heard only the tone. Eventually, the normal mice adjusted their responses so they did not freeze after hearing the tone. However, the mutant continued to respond as if they expected a foot shock to follow.

The researchers sought additional support for their conclusion that the absence of PERK may contribute to impaired behavioral flexibility in human neurological disorders. To do so, they conducted postmortem analyses of human frontal cortex samples from patients afflicted with schizophrenia, who often exhibit behavioral inflexibility, and unaffected individuals. The samples from the control group showed normal levels of PERK while those from the schizophrenic patients had significantly reduced levels of the protein.

"A rapidly expanding list of neurological disorders and neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease, and Fragile X syndrome, have already been linked to aberrant ," explained Eric Klann, a professor in NYU's Center for Neural Science and one of the study's co-authors. "Our results show the significance of PERK in maintaining behavioral flexibility and how its absence might be associated with . Further studies clarifying the specific role of PERK-regulated synthesis in the brain may provide new avenues to tackle such widespread and often debilitating neurological disorders."

Journal reference: Cell Reports search and more info website

Provided by New York University search and more info website

5 /5 (4 votes)  

Filter


Move the slider to adjust rank threshold, so that you can hide some of the comments.


Display comments: newest first

foofighter
May 24, 2012

Rank: not rated yet
i thought behavior was the domain of the soul? isn't that right kevinrtrschokesonspoogeandenvelopesmanmeatwithhisanalsphincter?
Rank 5 /5 (4 votes)
Relevant PhysicsForums posts

More news stories

Computational tool translates complex data into simplified 2-dimensional images

In their quest to learn more about the variability of cells between and within tissues, biomedical scientists have devised tools capable of simultaneously measuring dozens of characteristics of individual ...

Medical research created 13 hours ago | popularity 5 / 5 (3) | comments 0 | with audio podcast

Now we know why old scizophrenia medicine works on antibiotics-resistant bacteria

In 2008 researchers from the University of Southern Denmark showed that the drug thioridazine, which has previously been used to treat schizophrenia, is also a powerful weapon against antibiotic-resistant bacteria such as ...

Medical research created May 17, 2013 | popularity 4 / 5 (4) | comments 0 | with audio podcast

SUMO wrestling cells reveal new protective mechanism target for stroke

Scientists investigating the interaction of a group of proteins in the brain responsible for protecting nerve cells from damage have identified a new target that could increase cell survival.

Medical research created May 17, 2013 | popularity 5 / 5 (1) | comments 0

How serotonin receptors can shape drug effects, from LSD to migraine medication

New findings by researchers carrying out experiments at the U.S. Department of Energy Office of Science's Advanced Photon Source (APS) help explain why some drugs that interact with two kinds of human serotonin ...

Medical research created May 17, 2013 | popularity 4 / 5 (1) | comments 0 | with audio podcast

Preventing blood poisoning

Peptide molecules derived from the body's natural immune system can help boost the body's defence against life-threatening blood poisoning, joint University research has uncovered.

Medical research created May 17, 2013 | popularity 4 / 5 (1) | comments 0 | with audio podcast


New theory on genesis of osteoarthritis comes with successful therapy in mice

Scientists at Johns Hopkins have turned their view of osteoarthritis (OA) inside out. Literally. Instead of seeing the painful degenerative disease as a problem primarily of the cartilage that cushions joints, ...

Researchers identify a potential new risk for sleep apnea: Asthma

Researchers at the University of Wisconsin have identified a potential new risk factor for obstructive sleep apnea: asthma. Using data from the National Institutes of Health (Heart, Lung, and Blood Institute)-funded Wisconsin ...

Study finds that sleep apnea and Alzheimer's are linked

A new study looking at sleep-disordered breathing (SDB) and markers for Alzheimer's disease (AD) risk in cerebrospinal fluid (CSF) and neuroimaging adds to the growing body of research linking the two.

'Gap' for HIV vaccine efforts after latest setback

The hunt for an HIV vaccine has gobbled up $8 billion in the past decade, and the failure of the most recent efficacy trial has delivered yet another setback to 26 years of efforts.

Ginger compounds may be effective in treating asthma symptoms

Gourmands and foodies everywhere have long recognized ginger as a great way to add a little peppery zing to both sweet and savory dishes; now, a study from researchers at Columbia University shows purified components of the ...

Alzheimer's leaves bilingual victims stranded in Canada

The devastating effect of Alzheimer's disease on bilingual people has been thrown into focus in Canada, where the sudden loss of a second language can leave sufferers feeling like strangers in their own country.