Lab Mice Became Anxious After Scientists Raised Heart Rate to 900 Beats per Minute

Heart rates of severeal lab mice were cranked up to 900 beats per minute by researchers, who also caused extreme anxiety in the mice.

According to a recent study with mice, which may have important ramifications for humans, anxiety can be produced by the body.

The study proved that raising a mouse's heart rate unnaturally causes the rodent to become anxious.

Emotional states have a physiological impact on our bodies, as scientists have known for a long time. However, it is still unknown whether a raised heart rate can cause anxiety or fear.

The study's Stanford University author, Karl Deisseroth, stated that their paper addresses a persistent issue that has motivated them in the lab and dates back at least to the American philosopher and psychologist William James.

James proposed in 1884 that bodily changes stand in for emotion and that, in a fundamental sense, the perception of the brain and feeling of these changes is the emotion.

Non-Invasive Optogenetic Pacemaker

Optogenetics, a method of using light to control particular cells, has been around for more than 20 years. These experiments were made possible by a quick and non-invasive version of optogenetics that the research team created over the previous three years.

The scientists created a non-invasive optogenetic pacemaker that gave them the ability to precisely control lab mice's cardiac rhythms and speed up their heartbeats to 900 beats per minute, which is 300 beats faster than the average resting rate.

They discovered that directly increasing the heart rate increased symptoms of anxiety, particularly in environments that might be dangerous. The brain's insular cortex was able to communicate with the heart muscle cells, mediating this effect.

The study, which was just published in the journal Nature, shows that brain activity is not the only factor in determining how a person would feel.

Mind and Body

Since many emotions, including happy emotions related to reward and social connection, as well as negative emotions related to anxiety, fear, and rage, are felt in the body, Deisseroth suggested that this might be a general principle.

The findings of the study indicate that the insular cortex is the primary region of the brain involved in the processes described, concluding that both the brain and body are mutually involved in the origins of emotional states, according to Dr. Antonio Giordano, the president of Sbarro Health Research Organization. Giordano was not involved in the study.

Beginning with James' theory, also known as the James-Lange theory, the question of how emotions relate to largely unconscious processes controlled by the autonomic nervous system-such as the heartbeat, the digestive system, etc.-has been a topic of discussion.

According to Very Well Mind, in the James-Lange theory of emotion, the body undergoes physical changes before an individual experiences an emotion. Emotions are essentially the result of how you interpret your physical sensations.

Applicability to Humans

According to this theory, seeing a bear makes a person feel afraid for example, according to Clifford Saper, a professor at Harvard Medical School who was also not involved in the study.

In response to seeing a bear, the cerebral cortex causes changes in blood pressure, heart rate, breathing, and other bodily functions. The "feeling" a person experiences is made up of all the sensations brought on by the autonomic response.

This study examines how the brain responds to a stressful stimulus, demonstrating that although it may not be the only factor, the brain's perception of changes in heart rate serves to enhance the emotional response.

Even though these animals are not the ideal models for the study, Deisseroth stated that it is "quite likely" that the conclusions could also apply to people.

According to Deisseroth, both species share the same fundamental circuitry and human epidemiology strongly correlates primary cardiac disorders with anxiety symptoms like panic attacks, Newsweek reports.