- Researchers have investigated whether increasing heart rate could induce anxiety in mice.
- They found that increased heart rate induces anxiety-like behavior in mice in risky environments.
- Further research is needed to know if these findings translate to humans.
Experiencing anxiety causes the heart to beat faster. However, whether the reverse is also true — that a faster heart rate can cause anxiety — has so far remained unclear.
Physiological theories of emotion proposed over a century ago suggest that emotions may arise from the body as well as the brain.
While the topic has been greatly discussed, until now, researchers have not had the experimental means to test the theory.
Recently, researchers used optogenetics to assess how increasing heart rate affects behavior in mice. Optogenetics involves bioengineering cells so they can be controlled by light.
The researchers found that increasing the heart rate induces anxious behavior in mice. The study appears in
Dr. Luana Marques, associate professor at Harvard Medical School, not involved in the study, told Medical News Today:
“This is a great study that pushes further the methodology that can help us to begin exploring the question of circuits that are involved in anxiety, but given [the] preliminary nature of the study, it will need replication and extension to humans to be able to be conclusive.”
To begin with, the researchers bioengineered muscle cells in the rodents’ hearts to make them sensitive to light. They then fitted the rodents with tiny vests that emitted red light that could pass through the body to control their heart rate. Each time the vest emitted a pulse of light, their heart muscles fired, causing a beat.
To test whether intermittent changes in heart rhythm could influence behavior, the researchers increased the mice’s heartbeat from 660 beats per minute (bpm) to 900 bpm for 500 milliseconds every 1,500 milliseconds.
They found that these intermittent changes did not alter…
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