In the brain, broken down 'motors' cause anxiety

February 7, 2013

When motors break down, getting where you want to go becomes a struggle. Problems arise in much the same way for critical brain receptors when the molecular motors they depend on fail to operate. Now, researchers reporting in Cell Reports on February 7, have shown these broken motors induce stress and anxiety in mice. The discovery may point the way to new kinds of drugs to treat anxiety and other disorders.

The study in mice focuses on one motor in particular, known as KIF13A, which, according to the new evidence, is responsible for ferrying serotonin receptors. Without proper transportation, those receptors fail to reach the surface of and, as a result, animals show signs of heightened anxiety.

In addition to their implications for understanding anxiety, the findings also suggest that defective molecular motors may be a more common and underappreciated cause of disease.

The video will load shortly
This video (S3 in the paper) shows the transport defect of the serotonin receptor in a KIF13A knock out neuron compared with a wild type neuron. Credit: Cell Reports, Zhou et al.

"Most proteins are transported in vesicles or as protein complexes by molecular motors," said Nobutaka Hirokawa of the University of Tokyo. "As shown in this study, defective motors could cause many diseases."

Scientists know that serotonin and serotonin receptors are involved in anxiety, aggression, and mood. But not much is known about how those players get around within cells. When Hirokawa's team discovered KIF13A at high levels in the brain, they wondered what it did.

The researchers discovered that mice lacking KIF13A show greater anxiety in both open-field and maze tests and suggest that this anxious behavior may stem from an underlying loss of serotonin receptor transport, which leads to a lower level of expression of those receptors in critical .

"Collectively, our results suggest a role for this molecular motor in anxiety control," the researchers wrote. Hirokawa says the search should now be on for anti-anxiety aimed at restoring the brain's serotonin receptor transport service.

Explore further: Researchers find why nicotine in cigarettes may relieve anxiety in smokers

More information: Cell Reports, Zhou et al.: "A Molecular Motor, KIF13A, Controls Anxiety by Transporting the Serotonin type 1a Receptor." dx.doi.org/10.1016/j.celrep.2013.01.014

Related Stories

Recommended for you

As cells age, the fat content within them shifts

January 19, 2017

As cells age and stop dividing, their fat content changes, along with the way they produce and break down fat and other molecules classified as lipids, according to a new University at Buffalo study.

What causes sleepiness when sickness strikes

January 19, 2017

It's well known that humans and other animals are fatigued and sleepy when sick, but it's a microscopic roundworm that's providing an explanation of how that occurs, according to a study from researchers at the Perelman School ...

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.