It has been known since the 1960s that certain sounds and music can relieve stress and pain. Since then, music therapy has been used in dental operations and post-operative treatments, among other things. A team led by Wenjie Zhou of the University of Science and Technology of China has now examined what happens in the brains of mice. The results were published in the journal Science.
Volume is more important
In order to find out if and how pain can be relieved by music, the experts first provoked a painful inflammatory reaction in the hind legs of the mice. They then exposed the animals to various acoustic stimuli. These included classical music, chaotic tone sequences, and white noise. Music and noise were also used at different distances and volumes.
It turned out that it wasn’t the kind of sounds that impacted mice’s pain perception. The decisive factor was the volume in relation to the ambient noise. If the volume is about five decibels (dB) – comparable to a whisper – above the ambient noise, it has a pain relieving effect. This lasted for up to two days after turning off the music and white noise. However, if the volume was ten, 15 or more decibels higher, this effect did not occur.
Connection between the auditory center and the thalamus
With the help of fluorescent proteins, the researchers visualized those areas in the brains of mice that react to the perception of pain and musical stimuli. They identified the neuronal networks between the auditory center in the rodent’s temporal lobe and the thalamus.
The thalamus is a kind of stimulus filter in the brain that transmits only the currently most important information to the cerebral cortex (cortex). This includes pain. If the neuronal networks discovered by the researchers are activated by sounds, this reduces the transmission of pain-related stimuli.
Possibility of new pain therapies
According to pain experts Rohini Kuner and Thomas Kuner of the University of Heidelberg, who classify the study results in an accompanying comment – also in the journal “Science” – the current results open up new possibilities for pain therapy that are less dangerous. the use of opioids and other pain relievers.
“Music and natural sounds have a positive effect on mood, relieve stress and relax the body. It is not unreasonable to think that these factors are also the basis of pain relief, “explain Rohini and Thomas Kuner. Further investigation is needed to make precise claims for human medicine, because:” It is not yet clear how animals perceive music ” , the two clarify.
According to Yuanyuan Liu, co-author of the study, imaging of the human brain has shown that there are likely areas similar to those found in the mouse brain. However, the results of the study should be treated with caution, as Kuner and Kuner point out: “Some noises can cause symptoms such as headaches or intensify them.” associated with migraine.