Featured Research

from universities, journals, and other organizations

Age-old anesthesia question awakened

Date:
March 21, 2012
Source:
National Institute of Standards and Technology (NIST)
Summary:
Why does inhaling anesthetics cause unconsciousness? New insights into this century-and-a-half-old question may spring from new research.

Different lipid molecules in the cell membrane separate out into an ordered region (red) and surrounding disordered regions (blue). Inhalation anesthetic molecules such as halothane cause these lipid regions to mix, potentially affecting the function of ion channel proteins found imbedded in the membrane.
Credit: Weinrich/NIH

Why does inhaling anesthetics cause unconsciousness? New insights into this century-and-a-half-old question may spring from research performed at the National Institute of Standards and Technology (NIST). Scientists from NIST and the National Institutes of Health have found hints that anesthesia may affect the organization of fat molecules, or lipids, in a cell's outer membrane -- potentially altering the ability to send signals along nerve cell membranes.

"A better fundamental understanding of inhaled anesthetics could allow us to design better ones with fewer side effects," says Hirsh Nanda, a scientist at the NIST Center for Neutron Research (NCNR). "How these chemicals work in the body is a scientific mystery that stretches back to the Civil War."

At the turn of the 20th century, doctors suspected inhaled anesthetics had some effect on cell membranes, an animal cell's outer boundary. Despite considerable investigation, however, no one was able to demonstrate that anesthetics produced changes in the physical properties of membranes large enough to cause anesthesia. But eventually, understanding of membrane function grew more refined as scientists learned more about ion channels.

Ion channels -- large proteins embedded in the relatively small lipid molecules forming the membrane -- are responsible for conducting electrical impulses along nerve cells in the brain and throughout our body. By a few decades ago, the prevailing theory held that inhaled anesthetics directly interacted with these protein channels, affecting their behavior in some fashion. But no one could find a single type of ion channel that reacted to anesthetics in a way pivotal enough to settle the matter, and the question remained open.

"That's where we picked up the thread," says Nanda. "We had been looking at how different types of lipid molecules affect ion channels."

While a cell membrane is a highly fluid film made of many different kinds of lipid molecules, the region immediately surrounding an ion channel often consists of a single type of lipids that form a sort of "raft" that is more ordered and less fluid then the rest of the membrane. When the team heard other researchers had found that disrupting these lipid rafts could affect a channel's function, they put to work their own previous experience working with the channels.

"We decided to test whether inhaled anesthetics could have an effect on rafts in model cell membranes," Nanda says. "No one had thought to ask the question before."

Using the NCNR's neutron and X-ray diffraction devices as their microscope, the team explored how a model cell membrane responded to two chemicals -- inhaled anesthetic, and another that has many of the same chemical properties as anesthetic but does not cause unconsciousness. Their finding showed a distinct difference in the way the lipid rafts responded: Exposing the membranes to an anesthetic caused the rafts to grow disorderly, freely mixing its lipids with the surrounding membrane, but the second chemical had a dramatically smaller effect.

While Nanda says the discovery does not answer the question definitively, he and his co-authors are following up with other experiments that could clarify the issue. "We feel the discovery has opened up an entirely new line of inquiry into this very old puzzle," he says.


Story Source:

The above story is based on materials provided by National Institute of Standards and Technology (NIST). Note: Materials may be edited for content and length.


Journal Reference:

  1. Michael Weinrich, Hirsh Nanda, David L. Worcester, Charles F. Majkrzak, Brian B. Maranville, Sergey M. Bezrukov. Halothane Changes the Domain Structure of a Binary Lipid Membrane. Langmuir, 2012; 28 (10): 4723 DOI: 10.1021/la204317k

Cite This Page:

National Institute of Standards and Technology (NIST). "Age-old anesthesia question awakened." ScienceDaily. ScienceDaily, 21 March 2012. <www.sciencedaily.com/releases/2012/03/120321132105.htm>.
National Institute of Standards and Technology (NIST). (2012, March 21). Age-old anesthesia question awakened. ScienceDaily. Retrieved August 28, 2014 from www.sciencedaily.com/releases/2012/03/120321132105.htm
National Institute of Standards and Technology (NIST). "Age-old anesthesia question awakened." ScienceDaily. www.sciencedaily.com/releases/2012/03/120321132105.htm (accessed August 28, 2014).

Share This




More Matter & Energy News

Thursday, August 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Australian Airlines Relax Phone Ban Too

Australian Airlines Relax Phone Ban Too

Reuters - Business Video Online (Aug. 26, 2014) Qantas and Virgin say passengers can use their smartphones and tablets throughout flights after a regulator relaxed a ban on electronic devices during take-off and landing. As Hayley Platt reports the move comes as the two domestic rivals are expected to post annual net losses later this week. Video provided by Reuters
Powered by NewsLook.com
Hurricane Marie Brings Big Waves to California Coast

Hurricane Marie Brings Big Waves to California Coast

Reuters - US Online Video (Aug. 26, 2014) Huge waves generated by Hurricane Marie hit the Southern California coast. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Chinese Researchers Might Be Creating Supersonic Submarine

Chinese Researchers Might Be Creating Supersonic Submarine

Newsy (Aug. 26, 2014) Chinese researchers have expanded on Cold War-era tech and are closer to building a submarine that could reach the speed of sound. Video provided by Newsy
Powered by NewsLook.com
Breakingviews: India Coal Strained by Supreme Court Ruling

Breakingviews: India Coal Strained by Supreme Court Ruling

Reuters - Business Video Online (Aug. 26, 2014) An acute coal shortage is likely to be aggravated as India's supreme court declared government coal allocations illegal, says Breakingviews' Peter Thal Larsen. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins