Featured Research

from universities, journals, and other organizations

Can You Feel The Heat? Tiny Hair-like Cell Structures, Your Cilia, Can

Date:
October 24, 2007
Source:
Johns Hopkins Medical Institutions
Summary:
Scientists have found a previously unrecognized role for tiny hair-like cell structures known as cilia: They help form our sense of touch. Cilia, tail-like projections found on the surface of cells, are perhaps best known as molecular flippers that help cells move around.

Cilia (bright red line) present in sensory nerve cells play an important role in our ability to sense touch and heat.
Credit: Johns Hopkins Medicine

Johns Hopkins researchers and colleagues have found a previously unrecognized role for tiny hair-like cell structures known as cilia: They help form our sense of touch.

Humans and genetically engineered mice lacking functional cilia respond more slowly to physical sensations such as exposure to hot water or a sharp poke with a stick. Results of the study, appearing in Proceedings of the National Academy of Sciences, will help doctors better understand diseases already linked to defective cilia like Bardet-Biedl syndrome (BBS) and polycystic kidney disease (PKD).

Cilia, tail-like projections found on the surface of cells, are perhaps best known as molecular flippers that help cells move around. Recently, researchers like Nico Katsanis, Ph.D., associate professor at Johns Hopkins' McKusick-Nathans Institute of Genetic Medicine, have found that cilia are important for many other biological processes, including three of our five senses: vision, hearing, and smell (ciliopathies are often characterized by loss or deficiency in these senses). "That leaves two unexplored possibilities," says Katsanis. "Taste and touch; we tried touch."

In the current study, the research team performed a pair of tests on both normal mice and engineered mice with defective cilia (Bbs -). To test heat sensitivity, they immersed the tails of the mice in warm water and measured how long before the mice flicked their tails. To test mechanical force, the researchers applied increasing (but not painful) pressure to the hind feet of mice until they withdrew their paws.

In both tests, the response time of the Bbs- mice to these external stimuli was longer. "These mutant mice can still feel the heat and pressure," explains Katsanis. "They just have a higher threshold for registering the sensation." Since the Bbs- mice had normal coordination on a spinning rotor, their slower responses likely weren't due to motor problems.

Norimasa Mitsuma, Ph.D., a postdoctoral student in Katsanis's lab, also demonstrated that the defective cilia weren't hindering brain function. He repeatedly dunked one hind paw in hot water for an hour and then carefully measured nerve activity at the base of the spinal cord - the junction between leg and brain. While regular mice displayed clear spinal nerve activity, Bbs- mice did not. This highlighted that the problem with Bbs- mice is that sensory information cannot reach the brain.

To find out whether people with inherited conditions that affect cilia also had different sensation thresholds, the researchers recruited nine patients with BBS, an inherited disorder characterized by obesity, polydactyly and vision loss.

The patients were asked to do seven simple perception tests, such as detecting the vibration of a tuning fork on their wrist or guessing the weight and shape of an object just by feeling it. All nine patients were less able than non-BBS patients to form the right response in at least some of the tests.

"This will certainly aid our efforts to both diagnose ciliopathies and relate to the patients," says Katsanis. "People with ciliopathies are often thought to have mental retardation or autism because they appear 'slow'. Now it appears that many aspects of their mental capacity may be just fine, they are just slow because they can't sense things as well as other individuals."

The research was funded by the National Institute of Child Health and Disease, the National Institute of Diabetes and Digestive and Kidney Disorders, the National Institute of General Medical Sciences, the National Institute of Neurological Disorders and Stroke, the Canadian Institutes of Health Research and the Wellcome Trust.

Authors on the paper are Travis Barr, Stephanie Coforio, Phillip Albrecht and Frank Rice of Albany Medical College; Peter Inglis, Brian Bradley and Michel Leroux of Simon Fraser University; Philip Beales of University College London; and Perciliz Tan, Norimasa Mitsuma, Susan Huang, Miguel A. Garcia-Gonzalez, Terry Watnick, Gregory Germino, Michael Caterina and Katsanis of Johns Hopkins.


Story Source:

The above story is based on materials provided by Johns Hopkins Medical Institutions. Note: Materials may be edited for content and length.


Cite This Page:

Johns Hopkins Medical Institutions. "Can You Feel The Heat? Tiny Hair-like Cell Structures, Your Cilia, Can." ScienceDaily. ScienceDaily, 24 October 2007. <www.sciencedaily.com/releases/2007/10/071022203111.htm>.
Johns Hopkins Medical Institutions. (2007, October 24). Can You Feel The Heat? Tiny Hair-like Cell Structures, Your Cilia, Can. ScienceDaily. Retrieved July 31, 2014 from www.sciencedaily.com/releases/2007/10/071022203111.htm
Johns Hopkins Medical Institutions. "Can You Feel The Heat? Tiny Hair-like Cell Structures, Your Cilia, Can." ScienceDaily. www.sciencedaily.com/releases/2007/10/071022203111.htm (accessed July 31, 2014).

Share This




More Plants & Animals News

Thursday, July 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Visitors Feel Part of the Pack at Wolf Preserve

Visitors Feel Part of the Pack at Wolf Preserve

AP (July 31, 2014) — Seacrest Wolf Preserve on the northern Florida panhandle allows more than 10,000 visitors each year to get up close and personal with Arctic and British Columbian Wolves. (July 31) Video provided by AP
Powered by NewsLook.com
Florida Panther Rebound Upsets Ranchers

Florida Panther Rebound Upsets Ranchers

AP (July 31, 2014) — With Florida's panther population rebounding, some ranchers complain the protected predators are once again killing their calves. (July 31) Video provided by AP
Powered by NewsLook.com
Dangerous Bacteria Kills One in Florida

Dangerous Bacteria Kills One in Florida

AP (July 31, 2014) — Sarasota County, Florida health officials have issued a warning against eating raw oysters and exposing open wounds to coastal and inland waters after a dangerous bacteria killed one person and made another sick. (July 31) Video provided by AP
Powered by NewsLook.com
Raw: Thousands Flocking to German Crop Circle

Raw: Thousands Flocking to German Crop Circle

AP (July 30, 2014) — Thousands of people are trekking to a Bavarian farmer's field to check out a mysterious set of crop circles. (July 30) Video provided by AP
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