Portland News

Anxiety study on mice hits breakthrough

Anxiety There has been several research on mental health over the last few decades with the goal of assisting millions of individuals globally.

Anxiety is one of the most frequent mental diseases that affects about 30% of individuals, causing their heart to race.

Some, on the other hand, believe that their racing heart increases their worry.

Yet, a new mouse research discovered that both fell into the same group.

A new finding

The study, published in the March 9 edition of Nature, indicates that in high-risk scenarios, a beating heart goes to a person’s mind, heightening anxiety.

The findings may provide a fresh viewpoint on understanding and treating anxiety disorders.

When scientists artificially elevated the heart rates of mice, they saw anxiety-like behavior.

They then soothed the mice by shutting off a brain region.

The brain and emotions

According to Stanford University neuroscientist Karl Deisseroth, the idea that physical sensations might contribute to emotions in the brain dates back to William James, the founder of psychology.

James established the theory that emotion follows what the body goes through in his 1890 book The Principles of Psychology, writing:

“We feel sorry because we cry, angry because we strike, afraid because we tremble.”

Interoception refers to the phenomenon in which the brain detects inside bodily impulses.

But, neuroscientist Anna Beyeler of the French National Institute of Health and Medical Research in Bordeaux believes it is impossible to verify whether these experiences contribute to emotion.

Beyeler investigates brain circuits associated with emotion, offering a remark on the findings:

“I’m sure a lot of people have thought of doing these experiments, but no one really had the tools.”

Read also: Risk Factors for Mental Health during the COVID-19 Pandemic

The new study

Karl Deisseroth devoted most of his career building instruments for this type of research.

He is one of the scientists that created optogenetics, a technology that employs viruses to change the genes of certain cells to respond to flashes of light.

Scientists can control the activity of the cells using a light switch.

Deisseroth and his colleagues affixed a small vest with a light over a mouse’s genetically altered heart to adjust its heart rate in the latest study.

When the mouse was turned off, its heart was beating at roughly 600 beats per minute.

The mouse’s heartbeat was synchronized with the flashing light at 900 beats per minute.

“It’s a nice reasonable acceleration [one mouse] would encounter in a time of stress or fear,” said Deisseroth.

The mice displayed anxiety-like behavior as their hearts began to race.

Mice generally withdrew to the walls and hid in dark corners in frightening situations.

In another scenario, when pressing a water lever occasionally resulted in a minor shock, mice with normal heart rates pressed on it without hesitation.

Mice with a racing heartbeat, on the other hand, would get thirsty.

“Everybody was expecting that, but it’s the first time that it has been clearly demonstrated,” said Beyeler.

Brain scans

The researchers examined the brains of the mice to seek for regions that could be processing the higher heart rate.

According to Deisseroth, one of the most prominent signals came from the posterior insula.

“The insula was interesting because it’s highly connected with interoceptive circuitry,” he said.

“When we saw that signal, [our] interest was definitely piqued.”

The scientists used additional optogenetics to lower activity in the posterior insula, which reduced the mice’s anxiety-like behaviors.

Despite the fact that the animals’ hearts were still pounding, they acted normally, spending more time in open regions of the mazes and pressing water levers without hesitation.

What next?

The study’s findings piqued the interest of many individuals, according to Wen Chen, branch chief of basic medical research for complementary and integrative health at the National Center for Complementary and Integrative Health in Bethesda.

“No matter what kind of meetings I go into, in the last two days, everybody brought up this paper,” said Chen.

According to Karl Deisseroth, the next stage is to investigate additional bodily areas that may influence anxiety.

“We can feel it in our gut sometimes, or we can feel it in our neck or shoulders,” he said.

Scientists may tension a mouse’s muscles or give it butterflies in the stomach to expose additional pathways that cause scared or anxiety-like behaviors using optogenetics.

Nevertheless, Beyeler believes that knowing the relationship between the heart and the brain might help doctors manage panic and anxiety.

But, the road from the lab to the clinic is more complicated than the path from the heart to the mind.

Image source: Autism Research News

Opinions expressed by Portland News contributors are their own.