Navigation Links
Researchers Discover Key to Body’s Ability to Detect Subtle Temperature Change

Scientists have long known the molecular mechanisms behind most of the body’s sensing capabilities. Vision, for example//, is made possible in part by rhodopsin, a pigment molecule that is extremely sensitive to light. It is involved in turning photons into electrical signals that can be decoded by the brain into visual information. But how the human body is able to sense a one-degree change in temperature has remained a mystery.

“For a long time, we didn’t know how temperature sensing was being carried out in animals,” said Jie Zheng, assistant professor in the Department of Physiology and Membrane Biology at the UC Davis School of Medicine. Huge progress was made in the last decade, Zheng said, when scientists discovered four ion channels sensitive to heat and two cold-sensitive ones.

“But, it was still unclear how only six temperature-sensor channels could cover wide ranges of temperature and still discriminate subtle differences,” Zheng said.

Using a novel method based on a technique first used by physicists, Zheng and his colleagues now have shown that the subunits of one channel can come together with subunits from another channel or coassemble in laboratory cell cultures to form new functioning channels. Assuming this process also happens in normal cells, it suggests a likely mechanism for the thermosensitivity seen in all animal cells, Zheng explained.

“We found that, by reassembling subunits we potentially have a lot more than six channel types responsible for the sensing of temperature,” he said.

The current findings are featured on the cover of the March issue of the Journal of General Physiology and were published online today.

Ion channels are pore-forming proteins found in the membranes of cells. They have the ability to open and close, regulating the flow of charged ions and controlling the voltage gradient found between the inside and outside of every living cell.

In the current study, Zheng and his colleagues focused on a group of ion channels called transient receptor potential (TRP) channels. In all, there are more than 20 TRP channels. Zheng’s group studied four of the six channels that have been shown to be involved in sensing temperature.

Previous studies concluded that different thermosensitive TRP channel subunits did not coassemble, Zheng said. He realized, however, that there were some technical limitations to the previous work. So, he and his colleagues decided to use a technique they developed last year, called spectra FRET. Spectra FRET, or spectroscopy-based fluorescence resonance energy transfer, allows the researcher to observe interactions between different channel subunits under a microscope.

“This technique allows us to look at the channel subunit composition in real-time in live cells,” Zheng said.

In the current experiments, cDNA coding for particular subunits is linked to cDNA coding for fluorescent proteins and then added to a culture of human embryonic kidney cells. The cells take up the DNA and then express the channel proteins, each now having a fluorescent protein tag. The researchers then observed the cells in the spectra FRET apparatus.

“Using spectra FRET, we were able to focus on just the signal from the plasma membrane,” Zheng explained. “What we found was that the subunits of one kind of heat-sensitive channel coassembled with subunits of other heat-sensitive channels to form new channels. This means that instead of four heat-sensitive channels we have a potential of 256 heat-sensitive channels with potentially different temperature sensitivity ranges.”

Zheng and his colleagues then confirmed their results using a technique called patch clamping that allowed them to record the electrical current flowing through individual open channels.

“Using these single-molecule recordings, we see many different channel types,” Zheng sa id. The next question we are trying to address is whether they really have different temperature sensitivity. We believe the answer is ‘yes,’ but we have to show that.”

Zheng also believes it is likely that the channels responsible for sensing cold coassemble in the same way. The cold- and heat-sensing subunits, however, do not seem to coassemble, he said.

The findings by Zheng and his colleagues promise to help solve the mystery of temperature sensitivity in animals once and for all. And, because the cells with these ion channels in their membranes are also the cells that sense pain, the basic knowledge they have provided may one day prove useful to scientists looking for novel remedies for pain.

“We have to re-examine everything from how people acclimate to hot climates to how they respond to spicy food based on the understanding that there are many more kinds of channels involved,” Zheng said.

Surce-Newswise
SRM
'"/>




Related medicine news :

1. Researchers urge caution in using ear tube surgery
2. Researchers Scale to assess the Severity of Epilepsy in Kids
3. Researchers trick Alzheimers Enzyme
4. Researchers find new HIV hiding place
5. New Hair in 15 Days Could Now Be A Possibility Say Researchers
6. Researchers developed world’s smallest toothbrus
7. Researchers discover receptor cells that can cause epilepsy
8. 15 Anti-SARS Drugs Identified By China-Europe Team of Researchers
9. Researchers reversed the process of memory loss
10. Researchers Identify Key Gene That May Help Brain Treatment
11. Researchers Discover Protein That Causes Malaria
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:6/27/2016)... Brooklyn, NY (PRWEB) , ... June 27, 2016 ... ... is using cutting edge technology to revolutionize the emergency ambulance transport experience for ... Many are aware of how Uber has disrupted the taxi industry through the ...
(Date:6/26/2016)... ... June 27, 2016 , ... Quality metrics are proliferating ... many ways they remain in the eye of the beholder, according to experts who ... of The American Journal of Managed Care. For the full issue, click here ...
(Date:6/26/2016)... Viejo, California (PRWEB) , ... June 26, 2016 , ... ... Final Cut Pro X. , "Film editors can give their videos a whole new ... said Christina Austin - CEO of Pixel Film Studios. , ProSlice Levels contains ...
(Date:6/26/2016)... ... ... a legally blind and certified personal trainer is helping to develop a weight loss fitness ... to fix the two major problems leading the fitness industry today:, , ... They don’t eliminate all the reasons people quit their exercise program ...
(Date:6/25/2016)... ... June 25, 2016 , ... ... and applications at AcademyHealth’s Annual Research Meeting June 26-28, 2016, at the Hynes ... important health care topics including advance care planning, healthcare costs and patient and ...
Breaking Medicine News(10 mins):
(Date:6/26/2016)... , June 27, 2016  VMS Rehab Systems, ... Board will take whatever measures required to build a ... stock which is currently listed on the OTC Markets-pink ... Company Chairman and CEO, "We are seeing an anomaly ... to understand, not only by the Company, but shareholders ...
(Date:6/24/2016)... N.J. , June 24, 2016  Collagen ... the design, development and manufacturing of collagen and ... regeneration announced today that Bill Messer ... and Marketing to further leverage the growing portfolio ... medical devices. Bill joins the Collagen ...
(Date:6/24/2016)... DUBLIN , June 24, 2016 ... and Markets has announced the addition of the ... their offering. ... products and provides an updated review, including its applications ... covering the total market, which includes three main industries: ...
Breaking Medicine Technology: