Brown neuroscientists have discovered why painkillers such as morphine and other opioids are so effective. The findings were released online on Feb. 11 and will appear in the March edition of Nature Neuroscience.
Jesica Raingo, a postdoctoral research associate, authored the findings along with Professor of Neuroscience Diane Lipscombe and former Brown graduate student Andrew Castiglioni PhD'06.
The scientists found that morphine and other opioids inhibit pain signals by blocking a special kind of N-type calcium channel, a protein that controls the passage of pain signals between nerve cells, according to a Feb. 15 news release by the University.
Lipscombe is an expert in N-type calcium channels, which are "cellular gatekeepers" that control the release of neurotransmitters at the synapse, the point of intersection between nerve cells. Neurotransmitters carry messages, including those for pain, between nerve cells.
Lipscombe and her team discovered a unique form of N-type channel in nociceptors, the neurons that carry pain signals to the spinal cord, that painkillers such as morphine affect. Typical N-type channels are made up of about 2,400 amino acids, but the channels discovered by Lipscombe's team differ from typical N-type channels by 14 amino acids, Lipscombe told The Herald. The team found that this small difference makes the channels especially sensitive and enables painkillers to take effect.
"We're hoping that companies can use that information to design better drugs that have the desirable actions of morphine without the negative central effects of morphine," Lipscombe said. Morphine and similar painkillers are highly addictive, and patients quickly become dependent and develop a tolerance to them, Lipscombe added.
"We've known that morphine and opioids were the antagonists of pain, but we were unclear exactly why," Lipscombe said. Her team's research "add(s) one tiny little piece of the puzzle. Providing an answer to something that has puzzled the field" was "satisfying," although it is difficult to know what role the findings will play in future research, she said.
Raingo has been working on this project for the last two-and-a-half years, according to Lipscombe, although some of the research used in the project dates back 15 years, to when Lipscombe first came to the University. Over the years, many people have been involved with the research, including several undergraduate students, she said.
Castiglioni's research "focused on how exon 37a impacts the function of the N-type (calcium) channel," he wrote in an e-mail to the Herald. He called the project a collaborative effort but added, "The calcium current recordings throughout the paper are all Jesica's data. Her results are beautiful to behold."
ANYONE ELSE WANNA BE PART OF THIS RESEARCH"?LMAO
