Neuroscientists explain inner workings of critical pain pathway

Feb 15, 2007

Whether they're fighting postoperative soreness or relieving chronic discomfort from conditions such as cancer, morphine and other opioids are powerful weapons against pain. Now, in research published online in Nature Neuroscience, Brown University scientists give one reason why these painkillers work so well.

The secret: They act on a special form of N-type calcium channel, the cellular gatekeepers that help control pain messages passed between nerve cells. By blocking these channels, pain signals are inhibited. These findings not only shed important light on how the body controls pain, they could be a boon to drug development.

"We've known that drugs such as morphine are highly effective at blocking calcium channels, but we've never known precisely why – until now," said Brown neuroscientist Diane Lipscombe, who led the research. "With this new understanding of how opioids work on calcium channels, drug companies could develop effective new painkillers."

Lipscombe, a professor in the Department of Neuroscience, is an expert in N-type calcium channels, critical players in the pain pathway. At the synapse – the point of connection between nerve cells – N-type channels control the release of neurotransmitters. These chemicals carry messages between nerve cells – messages that include sensations of pain. So if you block N-type channels, you can block pain.

But all of these channels shouldn't be closed, Lipscombe explained. That's because some pain signals – "That stove is hot!" – are needed to survive. "You don't want to shut off all pain signals," she said. "You just want to dampen some of them down."

In 2004, Lipscombe and her colleagues discovered a unique form of the N-type channel in nociceptors, neurons that carry pain signals to the spinal cord. These are the channels that opioids act on. But what makes the channels in nociceptors so special?

In their new work, Lipscombe and her team uncover the answer. All N-type channels are made up of a string of about 2,400 amino acids. In nociceptor N-type channels, that string differs by a mere 14 amino acids, Lipscombe and her team learned. This small difference in molecular make-up makes these channels much more sensitive to the pain-blocking action of opioids.

"In nociceptor N-type channels, you get double-barreled inhibitory action," she explained.

Source: Brown University

Explore further: Antioxidant found in grapes uncorks new targets for acne treatment

add to favorites email to friend print save as pdf

Related Stories

Nanoparticles give up forensic secrets

2 hours ago

A group of researchers from Switzerland has thrown light on the precise mechanisms responsible for the impressive ability of nanoparticles to detect fingermarks left at crime scenes.

Study shows sharks have personalities

3 hours ago

Some sharks are 'gregarious' and have strong social connections, whilst others are more solitary and prefer to remain inconspicuous, according to a new study which is the first to show that the notorious ...

Desktop device to make key gun part goes on sale in US

4 hours ago

The creator of the world's first 3D plastic handgun unveiled Wednesday his latest invention: a pre-programmed milling machine that enables anyone to easily make the core component of a semi-automatic rifle.

Twitter-funded lab to seek social media insights

4 hours ago

A new Twitter-funded research project unveiled Wednesday, with access to every tweet ever sent, will look for patterns and insights from the billions of messages sent on social media.

Recommended for you

Scientists aim to give botox a safer facelift

9 hours ago

New insights into botulinum neurotoxins and their interactions with cells are moving scientists ever closer to safer forms of Botox and a better understanding of the dangerous disease known as botulism. By comparing all known ...

User comments : 0