Body’s “Natural Opioids” Affect Brain Cells Much Differently than Morphine
A new study led by UC San Francisco scientists shows that brain cells, or neurons, react differently to opioid substances created inside the body – the endorphins responsible for the “natural high” that can be produced by exercise, for example – than they do to morphine and heroin, or to purely synthetic opioid drugs, such as fentanyl. The researchers say their findings may help explain why the use of synthetic opioids can lead to addiction.
Since both synthetic opioids and the natural, “endogenous” opioids produced in the brain bind to and activate opioid receptors on the surface of nerve cells, scientists have long assumed that both types of molecules target the same cellular systems. But the new research reveals that these molecules also activate opioid receptors inside cells, and that the locations of these activated intracellular receptors differ between natural and synthetic opioids.