Light, Not Pain-Killing Drugs Used to Activate Brain’s Opioid Receptors

A groundbreaking new treatment may replace opioid drugs for sufferers of intense pain by combining a light-gathering protein with opioid receptors, in order to activate those pathways using light rather than traditional chemical reactions. Researchers from Washington University School of Medicine in St. Louis published their findings in the journal Neuron, detailing their formulation of a light-detecting protein based on those found within the retinas of the eye, and implanting it in opioid receptors of mouse brains. Following this procedure, light emitting diodes (LEDs) the size of a human hair were installed within the reward response section of the brain in order to remotely activate opioid receptors without the use of drugs. “It’s been difficult to determine exactly how opioid receptors work because they have multiple functions in the body,” explained the author. “These receptors interact with pain-killing drugs called opiates, but they also are involved in breathing, are found in the gastrointestinal tract and play a role in the reward response.” The researchers were able to vary the animals’ response depending on the amount and type of light emitted by the LED. Different colors of light, longer and shorter exposure to light, and whether the light pulsed or was constant all produced slightly different effects. To learn more about this study, click here.