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Can music soothe pain? A new study in mice finds that listening to Mozart alongside taking standard pain medication works better than drugs alone. The researchers used two pain models: the carrageenan model, which mimics inflammation-related pain; and plantar incision, which replicates surgical pain.
They split the mice into two groups of five to eight animals. They exposed the control group to only ambient noise, while they played the experimental group three 3-hour segments of Mozart each day for 3 weeks. Interestingly, the researchers did not choose the segments of music at random. As Grzegorz Bulaj, Ph.D. — an associate professor in medicinal chemistry — explains:
“Music is like DNA. We had musicians analyze sequences of several Mozart pieces to optimize the playlist. This was exciting but challenging to integrate these musical analyses into neuropharmacology.” They ran the study four times, each time using a different drug that can reduce pain. These drugs were ibuprofen, cannabidiol, levetiracetam, and a galanin analog called NAX 5055.
Both the control and the music groups received doses considered suboptimal. The ibuprofen trials produced the most striking results. In the group that listened to music, pain responses in the carrageenan model dropped by 93 percent, compared with the mice that took ibuprofen but did not listen to music.
Also, in the carrageenan model, music and cannabidiol reduced swelling by 21 percent. NAX 5055 plus music reduced swelling by 9 percent. In the surgical pain model, music also significantly reduced some but not all responses to pain.
Using animal models comes with certain difficulties, but in this case, the scientists’ use of a mouse model makes it more interesting; it removes the complex human psychological response to music. One is almost tempted to believe that harmony has an intrinsic healing quality. Although it may seem surprising that a rodent might physiologically respond to music, this is not the first time that scientists have demonstrated this. Research into mice and music has a long pedigree.
For instance, the authors of a review of 42 relevant studies — published in December 2018 — found that “[m]usic interventions seem to improve brain structure and neurochemistry; behavior; immunology; and physiology in rodents.” Music exposure was linked with statistically significantly improved spatial and auditory learning, reduced anxiety-related behavior, and increased immune response.
The scientists did not design this study to unpick how music might reduce pain, but they do outline some theories. For instance, earlier research demonstrated that music upregulates the production of brain-derived neurotrophic factor (BDNF). This protein supports neurons and encourages the growth of neurons and synapses. In the long-term, BDNF inhibits pain sensitivity.
Other theories that the study authors consider are music’s ability to impact parasympathetic tone, cortisol levels, pro-inflammatory cytokines, the dopaminergic system, and opioid receptors. It will take a great deal more work to tease apart the mechanisms involved, and the answer is likely to involve all of the above and more.