Link found between placebo effect and previously unrelated parts of the brain

Chronic pain patients have limited treatment options, often relying on medications like opioids that come with harmful side effects and a high risk of addiction. A new study in mice, published in the journal Current Biology, suggests a new way to harness the placebo effect to treat chronic pain. By activating specific neurons in the brain associated with pain relief, the researchers were able to create an environment in which mice associated pain relief with the environment, providing a lasting placebo effect.

Research conducted by Fan Wang’s team

Fan Wang, a neurobiologist at the Massachusetts Institute of Technology, led the study. Wang and her team investigated how neurons in the central amygdala could be “reverse engineered” to mimic the placebo effect, according to a report on Science.org. They conditioned mice previously afflicted with chronic chemotherapy-induced pain to associate a specific environment with pain relief. Even when the neuronal stimulation was removed, the mice still showed pain relief, showing reduced pain-related behaviors.

The Role of Pain-Suppressing Neurons

The placebo effect was achieved without reactivating pain-suppressing neurons, suggesting a distinct brain mechanism driving this response. The researchers found that the placebo effect also occurred, albeit weaker, when the mice were given morphine instead of neural stimulation.

Potential implications for human treatment

Fabrizio Benedetti, a placebo expert at the University of Turin Medical School, says the study supports the idea that placebos and drugs may share common mechanisms. While the placebo effect in humans involves complex factors such as social interactions, these animal models can help deepen our understanding of pain management.

Dr. Benedict Alter of the University of Pittsburgh notes that while there is still a long way to go before this research can be applied to humans, the findings have great potential for drug-free treatments.