In a study published in Science, researchers at Karolinska Institutet describe the neural processes behind how morphine relieves pain. This is valuable knowledge because the drug has such serious side effects. 

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.  Morphine acts on several central and peripheral pain pathways in the body, but the neural processes behind the pain relief have not previously been fully understood.