|Sharpen Up, Sleepyhead
Sleepless nights beget foggy thinking. Millions of people know this all too well, but the mechanisms by which sleep deprivation affects brain function have been a longstanding mystery. A recent experiment on sleep-deprived mice may hold the beginnings of a solution—and a potential way to reverse the effect. A research team led by Penn biology professor Ted Abel found that mice deprived of sleep had reduced levels of cAMP, a molecule crucial to the formation of new synapses in the hippocampus, a brain area critical to memory and learning. They also had reduced levels of an enzyme called PDE4.
The team then treated the mice with a PDE inhibitor, which rescued the deficits in cAMP signaling and synaptic connections, thereby counteracting some of the memory consequences of sleep deprivation. The finding was published in an October issue of Nature. “Our work identifies specific molecular changes in neurons caused by sleep deprivation,” said Abel. “Future work on this target protein promises to reveal novel therapeutic approaches to treat cognitive deficits that accompany sleep disturbances seen in sleep apnea, Alzheimer’s disease, and schizophrenia.”
Eat Your Broccoli, Already
From colon cancer to cataracts, broccoli is lauded as the prince of prevention in the nutritional realm. Recently a team of Penn researchers turned up evidence of another potential health benefit to add to the vegetable’s résumé. It contains a dietary antioxidant that protects against damages caused by chemicals generated by the body’s inflammatory response to infection and injury.
Physiology professor Zhe Lu and two colleagues have shown that the antioxidant thiocynate—which is also found in cauliflower—protects lung cells from injuries caused by accumulations of hydrogen peroxide and hypochlorite, the active ingredient in household bleach. It also reduces the toxicity of MPO, an enzyme released from germ-fighting white blood cells during inflammation, in cells that line blood vessels. The finding, which appeared in the Proceedings of the National Academy of Sciences in November, raises the possibility that an inadequate dietary supply of thiocynate could worsen inflammatory diseases such as cystic fibrosis, diabetes, heart disease, and neurodegeneration.
The Water Is High
The sea level at two nearby sites in North Carolina rose three times more quickly in the 20th century than during the last 500 years. That’s according to an international team of researchers led by Andrew Kemp, a postdoctoral researcher in Penn’s Department of Earth and Environmental Science. They based their conclusions on the accumulation of organic sediment in two salt marshes, a natural archive that enables a high-resolution reconstruction of historical tide levels through radiometric isotopes and stratigraphic age markers. The acceleration in the rate of sea-level rise at these sites appears to have begun between 1879 and 1915, a period of rapid industrial change. The findings appeared in the November issue of Geology.
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Last modified 12/22/09