Featured Research

from universities, journals, and other organizations

Why Do Rats Die Younger Than Humans? Newly Discovered Biological Clock Provides Tantalizing Clues

Date:
April 6, 2008
Source:
New York University
Summary:
A newly discovered biological clock, or biological rhythm, controls many metabolic functions and is based on the circadian rhythm, which is a roughly 24-hour cycle that is important in determining sleeping and feeding patterns, cell regeneration, and other biological processes in mammals.

A 3-D microscopic view of bone from a human femur showing incremental growth lines corresponding to a biological rhythm that repeats itself every eight days. The black hole at the top is a blood vessel canal.
Credit: Dr. Tim Bromage

A New York University dental professor has discovered a biological clock linking tooth growth to other metabolic processes. This clock, or biological rhythm, controls many metabolic functions and is based on the circadian rhythm, which is a roughly 24-hour cycle that is important in determining sleeping and feeding patterns, cell regeneration, and other biological processes in mammals.

The newly discovered rhythm, like the circadian rhythm, originates in the hypothalamus, a region of the brain that functions as the main control center for the autonomic nervous system. But unlike the circadian rhythm, this clock varies from one organism to another, operating on shorter time intervals for small mammals, and longer ones for larger animals. For example, rats have a one-day interval, chimpanzees six, and humans eight.

NYU dental professor Dr. Timothy Bromage discovered the rhythm while observing incremental growth lines in tooth enamel, which appear much like the annual rings on a tree. He also observed a related pattern of incremental growth in skeletal bone tissue -- the first time such an incremental rhythm has ever been observed in bone.

Reporting his findings at the 37th Annual Meeting of the American Association for Dental Research, Bromage said, "The same biological rhythm that controls incremental tooth and bone growth also affects bone and body size and many metabolic processes, including heart and respiration rates. In fact, the rhythm affects an organism's overall pace of life, and its life span. So, a rat that grows teeth and bone in one-eighth the time of a human also lives faster and dies younger."

Humans have by far the most variation in these long-term incremental growth rhythms, with some humans clocking as few as five days, and others as many as ten. Correspondingly, humans have the most variability in body size among mammals.

Future research will assess whether there is a link between slower growth rhythms and growth disorders. Since the autonomic nervous system controls human behavior, future research will also assess whether growth rhythms can be linked to variations in human behavior.

Dr. Bromage is an Adjunct Professor of Basic Science and Craniofacial Biology and of Biomaterials and Biomimetics at the NYU College of Dentistry.


Story Source:

The above story is based on materials provided by New York University. Note: Materials may be edited for content and length.


Cite This Page:

New York University. "Why Do Rats Die Younger Than Humans? Newly Discovered Biological Clock Provides Tantalizing Clues." ScienceDaily. ScienceDaily, 6 April 2008. <www.sciencedaily.com/releases/2008/04/080405095747.htm>.
New York University. (2008, April 6). Why Do Rats Die Younger Than Humans? Newly Discovered Biological Clock Provides Tantalizing Clues. ScienceDaily. Retrieved October 21, 2014 from www.sciencedaily.com/releases/2008/04/080405095747.htm
New York University. "Why Do Rats Die Younger Than Humans? Newly Discovered Biological Clock Provides Tantalizing Clues." ScienceDaily. www.sciencedaily.com/releases/2008/04/080405095747.htm (accessed October 21, 2014).

Share This



More Health & Medicine News

Tuesday, October 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

CDC Revamps Ebola Guidelines After Criticism

CDC Revamps Ebola Guidelines After Criticism

Newsy (Oct. 21, 2014) The Centers for Disease Control and Prevention have issued new protocols for healthcare workers interacting with Ebola patients. Video provided by Newsy
Powered by NewsLook.com
'Cadaver Dog' Sniffs out Human Remains

'Cadaver Dog' Sniffs out Human Remains

AP (Oct. 21, 2014) Where's a body buried? Buster's nose can often tell you. He's a cadaver dog, specially trained to find human remains and increasingly being used by law enforcement and accepted in courts. These dogs are helping solve even decades-old mysteries. (Oct. 21) Video provided by AP
Powered by NewsLook.com
How Nigeria Beat Its Ebola Outbreak

How Nigeria Beat Its Ebola Outbreak

Newsy (Oct. 20, 2014) The World Health Organization has declared Nigeria free of Ebola. Health experts credit a bit of luck and the government's initial response. Video provided by Newsy
Powered by NewsLook.com
How Detroit's Money Woes Led To U.N.-Condemned Water Cutoffs

How Detroit's Money Woes Led To U.N.-Condemned Water Cutoffs

Newsy (Oct. 20, 2014) The United Nations says water is a human right, but should it be free? Detroit has cut off water to residents who can't pay, and the U.N. isn't happy. Video provided by Newsy
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:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

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