| ▲ Research results have been published that a fast heart rate itself can cause anxiety. (Photo = DB) |
[메디컬투데이=한지혁 기자] Studies have shown that a rapid heart rate can cause anxiety in itself.
The results of a mouse study carried out to find out whether an increase in heart rate can cause anxious feelings have been published in the journal ‘Nature’.
Often when we feel anxious, our heart beats faster. Conversely, however, it is still unclear whether a rapid heart rate itself can cause anxiety.
According to the theory of the physiology of emotions, first proposed about 100 years ago, the body as well as the brain can produce emotions. Although discussions on these concepts have continued, no effective method has been proposed to test the theory in practice.
In this study, the researchers used cells bioengineered to be controlled by light to evaluate the effect of increasing heart rate on mouse behavior.
The mice’s cardiac muscle cells were modulated by infrared light, which allowed the researchers to artificially set the heart rate in the mouse models. They started at 660 beats per minute and increased the mice’s heart rate to 900 in 500 milliseconds, repeating this every 1500 milliseconds.
These intermittent changes in heart rate did not change the behavior of the mice or their response to pain in the familiar space. However, mice whose heart rate increased in an unfamiliar environment such as a maze showed less curiosity compared to the control group. This suggests that the increase in heart rate has caused anxiety in the mice.
Also, when mice were trained to press a lever to get a drink followed by a random shock, the mice whose heart rate increased were less likely to press the lever.
To understand how heart rate triggers anxiety, the researchers also observed brain activity in mouse models. The results showed that an increase in heart rate increases the activity of brain regions responsible for emotions and body signals associated with anxiety.
Experts said that the current theory that the connection between the heart and the brain is very likely to be bidirectional has been partially confirmed through this study, and that the sympathetic nervous system or hormones such as cortisol and adrenaline could be connected.
They also added that understanding why patients suffering from conditions such as arrhythmia and tachycardia experience anxiety, and treating these conditions could help them resolve their psychiatric problems.
Based on these new findings, the researchers hope to investigate how the brain and behavior affect other body systems, such as the digestive system, skin cells and facial muscles.
Medical Today Reporter Han Ji-hyeok (hanjh3438@mdtoday.co.kr)
[저작권자ⓒ 메디컬투데이. 무단전재-재배포 금지]
