Master clock in mouse brain with the nuclei of the clock cells shown in blue and the VIP molecule shown in green. Credit: Cristina Mazuski in the lab of Erik Herzog, Washington University in St. Louis.
Our biological clocks play a large part in influencing our sleep patterns, hormone levels, body temperature and appetite. A small molecule called VIP, shown in green, enables time-keeping neurons in the brain’s central clock to coordinate daily rhythms. New research shows that, at least in mice, higher doses of the molecule can cause neurons to get out of synch. By desynchronizing mouse neurons with an extra burst of VIP, Erik Herzog of Washington University in St. Louis found that the cells could better adapt to abrupt changes in light (day)-dark (night) cycles. The finding could one day lead to a method to reduce jet lag recovery times and help shift workers better adjust to schedule changes.
Washington University in St. Louis News Release
Circadian Rhythms Fact Sheet
Tick Tock: New Clues About Biological Clocks and Health Article from Inside Life Science
A Light on Life’s Rhythms Article from Findings Magazine
Credit: Yaron Fuchs and Samara Brown in the lab of Hermann Steller, Rockefeller University.
Whether injured by a scrape, minor burn or knife wound, skin goes through the same steps to heal itself. Regrowing hair over new skin is one of the final steps. All the hair you can see on your body is non-living, made up of “dead” cells and protein. It sprouts from living cells in the skin called hair follicle stem cells, shown here in red and orange. For more pictures of hair follicle stem cells—and many other stunning scientific images and videos—go to the NIGMS Image and Video Gallery.
Rockefeller University News Release
Credit: Huey Huang, Rice University.
A new video, starring the toxin in bee venom, might help scientists design new drugs to combat bacterial infections. The video, by Rice University biophysicist Huey Huang , condenses 6.5 minutes into less than a minute to show how the toxin, called melittin, destroys an animal or bacterial cell.
What looks like a red balloon is an artificial cell filled with red dye. Melittin molecules are colored green and float on the cell’s surface like twigs on a pond. As melittin accumulates on the cell’s membrane, the membrane expands to accommodate it. In the video, the membrane stretches into a column on the left.
When melittin levels reach a critical threshold, countless pinhole leaks burst open in the membrane. The cell’s vital fluids—red dye in the video—leak out through these pores. Within minutes, the cell collapses.
Many organisms use such a pore-forming technique to kill attacking bacterial cells. This research reveals molecular-level details of the strategy, bringing pharmaceutical scientists a step closer to harnessing it in the design of new antibiotics.
Rice University News Release
Credit: Phillip Klebba, Kansas State University.
It looks like a fluorescent pill, but this image of an E. coli cell actually shows a new potential target in the fight against infectious diseases. The green highlights a protein called TonB, which is produced by many gram-negative bacteria, including those that cause typhoid fever, meningitis and dysentery. TonB lets bacteria take up iron from the host’s body, which they need to survive. New research from Phillip Klebba of Kansas State University and his colleagues shows how TonB powers iron uptake. When TonB spins within the cell envelope (the bacteria’s “skin”) like a tiny motor, it produces energy that lets another protein pull iron into the cell. This knowledge may lead to the development of antibiotics that block the motion of TonB, potentially stopping an infection in its tracks.
Kansas State University News Release
Other Cool Images