Humans and zebra fish share mechanisms that regulate our circadian system, says TAU researcher
Circadian rhythms — the natural cycle that dictates our biological processes over a 24-hour day — does more than tell us when to sleep or wake. Disruptions in the cycle are also associated with depression, problems with weight control, jet lag and more. Now Prof. Yoav Gothilf of Tel Aviv University‘s Department of Neurobiology at the George S. Wise Faculty of Life Sciences is looking to the common zebrafish to learn more about how the human circadian system functions.
Ever since Falstaff, fatness has been associated with jollity. According to psychologists at Lakehead University in Canada, the “jolly fat” hypothesis might actually be true, at least among women. Not only have they found a link, they suggest a mechanism, too: estrogen.
They put forward the idea that body fat protects women again negative moods. In other words, the fatter a woman is, the less depressed she gets.
In the two-part research, the team looked at Body Mass Index (BMI), a measure that takes into account Continue reading →
DETROIT – Jet lag may soon be history thanks to scientists who have discovered the exact brain cell that sends us to sleep or keeps us awake.
The finding by University of Michigan mathematicians and their British colleagues overturns a long-held theory about our internal clock.
Understanding how the human biological clock works is an essential step toward correcting sleep problems like insomnia and jet lag. New insights about the body’s central pacemaker might also, someday, advance efforts to treat diseases influenced by the internal clock, including cancer, Alzheimer’s disease and mood disorders, said University of Michigan mathematician DanielForger.
“Knowing what the signal is will help us learn how to adjust it, in order to help people,” said Forger, an associate professor of mathematics and a member of the U-M’s Center for Computational Medicine and Bioinformatics.
“We have cracked the code, and the information could have a tremendous impact on all sorts of diseases that are affected by the clock,” the expert added.
The body’s main time-keeper resides in a region of the central brain called the suprachiasmatic nuclei, or SCN. For decades, researchers have believed that it is the rate at which SCN cells fire electrical pulses—fast during the day and slow at night—that controls time-keeping throughout the body.
Imagine a metronome in the brain that ticks quickly throughout the day, then slows its pace at night. The rest of the body hears the ticking and adjusts its daily rhythms, also known as circadian rhythms, accordingly.
That’s the idea that has prevailed for more than two decades. But new evidence compiled by Forger and his colleagues shows that “the old model is, frankly, wrong,” Forger said.
The true signaling mechanism is very different: The timing signal sent from the SCN is encoded in a complex firing pattern that had previously been overlooked, the researchers concluded.
Forger and U-M graduate student Casey Diekman, along with Dr. Mino Belle and HughPiggins of the University of Manchester in England, report their findings in Science.