A daily scheduled meal is a potent time-giving cue that can reset the physiological timing of most organs, including the liver. In terms of animal behavior, a daily scheduled meal elicits anticipatory bouts of locomotor activity and changes in body temperature. These food-anticipatory behaviors are believed to be under the control of a food-entrainable mechanism--that is, a timing mechanism within the body that is set by food intake--but how this mechanism works at the molecular level is unknown.
In the new work, the researchers have found the first evidence that a single gene mutation can render mice totally unable to predict the time of food availability. Studying mice, they found that this lack of food anticipation at both behavioral and physiological levels is specifically associated with a mutation in the Period 2 gene, a gene that previous work had shown to play an important role in the brain's ability to run its central circadian clock according to daylight.
The researchers found that, interestingly, synchronization of timing between organs by scheduled meals is not affected by the Period 2 mutation, indicating that this gene is not crucial for scheduled food availability to affect the physiological coordination of tissues outside the central nervous system.
The authors of the study point out that the work they report provides a tool for investigating the brain's cerebral clockwork responsible for predicting mealtime--with this tool in hand, it will be possible to anatomically localize areas of the brain that are involved in food anticipation. Looking forward, the researchers expect that this will allow the study of how these areas interact with other brain regions responsible for other types of behavior, such as learning, memory, and the experience of pleasure.
Knowledge of the mechanism of synchronizing an organism's physiology to mealtime is expected to improve therapies for counteracting disorders that have their roots in a disturbed circadian system, such as sleep problems, eating disorders, obesity, and depression.
Related biology news :
1. Jumping gene helps explain immune systems abilities
2. Protein helps regulate the genes of embryonic stem cells
3. Scientists reveal the shape of a protein that helps retroviruses break into cells
4. Thai spice helps cut blood sugar swings
5. Chemists synthesize molecule that helps body battle cancers, malaria
6. Ancient DNA helps clarify the origins of two extinct New World horse species
7. Massey Cancer Center researcher helps to identify a piece of the cancer puzzle
8. Study: Well-known protein helps stem cells become secretory cells
9. Beyond genes: Lipid helps cell wall protein fold into proper shape
10. Simple sea sponge helps scientists understand tissue rejection
11. New technique helps identify multiple DNA regulatory sites