Researchers have shown how it is possible to treat pain in mice through the use of sound. The breakthrough could offer alternative ways for pain management that ae not reliant upon addictive medications.
Researchers at the U.S. National Institute of Dental and Craniofacial Research have identified the neural mechanisms through which sound blunts can blunt pain, by using the animal model.
That sound can help to alleviate pain has been established for decades; that is new is deciphering the analgesic mechanism by which this takes place. Since the 1960s researchers have identified that music can aid the alleviation of acute and chronic pain, such as pain from surgery.
For the study, scientists exposed mice with inflamed paws to three types of sound. These sounds included a pleasant piece of classical music, an unpleasant rearrangement of the same piece, and white noise.
It was found that all three types of sound, when played at a low intensity relative to background noise (close to the level of a whisper) reduced pain sensitivity. However, higher intensities of the same sounds had no effect on animals’ pain responses.
Therefore, the key determinant was the sensitivity of the sound rather than the nature of the sound itself.
In order to identify the brain circuitry impacting this effect, the researchers used non-infectious viruses together with fluorescent proteins as the mechanism to trace connections between brain regions.
This inquiry pinpointed the route from the auditory cortex, which receives and processes information about sound, to the thalamus, which functions as a relay station for sensory signals, including pain, from the body. The application of noise and he desired intensity reduces the activity of neurons at the receiving end of the pathway in the thalamus.
Subsequent research showed that in the absence of sound, suppressing the pathway mimicked the pain-blunting effects of low-intensity noise; in contrast, turning on the pathway restored the sensitivity to pain.
The next step will be to test out whether the same effect and same pathways exist with humans. Unlocking this could be the key to developing new forms of pain management treatment.
The research appears in the journal Science, titled “Sound induces analgesia through corticothalamic circuits.”
