Researchers have made a groundbreaking discovery on how morphine relieves pain by activating a specific group of neurons in the brain, termed the ‘morphine ensemble.’ This finding could pave the way for safer pain management strategies and reduce the severe side effects associated with morphine, such as addiction and overdose.
Key Takeaways
- Morphine relieves pain by activating a specific set of neurons in the rostral ventromedial medulla (RVM), known as the ‘morphine ensemble.’
- Inactivating these neurons eliminates morphine’s pain-relieving effects, while reactivating them restores pain relief.
- Deeper knowledge of these pathways could lead to safer pain management strategies and reduce morphine’s harmful side effects.
The Morphine Ensemble
Morphine is a powerful painkiller that belongs to the group of opioids. It blocks signals in the pain pathways and also increases feelings of pleasure. However, the neural processes behind its pain relief have not been fully understood until now.
Researchers have investigated how morphine relieves pain using several new experimental approaches. By exposing laboratory animals to morphine, they managed to ‘capture’ the neurons activated by the drug. This allowed them to identify, classify, and synthetically control the neurons involved in pain relief.
Activation and Inactivation of Neurons
The study revealed that morphine affects a selected set of neurons in the brain’s rostral ventromedial medulla (RVM). These neurons form a ‘morphine ensemble,’ a group whose change in activity leads to pain relief.
When researchers synthetically inactivated the neurons in this group, they completely abolished the effects of morphine on pain. Reactivating the neurons similarly recreated the pain relief.
A particular type of neuron that wires to the spinal cord plays a central role in the ‘morphine ensemble.’ In the spinal cord, these neurons connect to inhibitory neurons that slow down pain signaling, thus preventing pain.
Implications for Pain Management
Morphine, when used as a medicine in healthcare, has potentially very serious side effects, including addiction, abuse, overdose, and death. According to Patrik Ernfors, professor at the Department of Medical Biochemistry and Biophysics at Karolinska Institutet and the leader of the study, it has been difficult to find strategies to treat pain without triggering these dangerous side effects.
He and his colleagues hope that deeper knowledge of how morphine works in the body can help reduce side effects in the future. The study is important because understanding the neural pathway and cells may explain how morphine can have such a powerful pain-relieving effect. It may also provide information on how these processes differ from those that induce feelings of euphoria, well-being, and addiction.
Future Research
In the next step, researchers aim to investigate why the pain relief provided by morphine decreases with long-term use. The study has been funded by the Swedish Research Council, the European Research Council, and the Knut and Alice Wallenberg Foundation.
Sources
- Morphine’s Pain Relief Mechanism Unveiled – Neuroscience News, Neuroscience News.
