Before their own central clocks develop, the brains of fetal rats detect their mother’s metabolic cycle to help regulate the expression of certain genes.
Two studies show that Plasmodium—the genus of protozoans that cause malaria—have an internal sense of time that synchronizes with their host’s circadian rhythms and allows the parasites to collectively attack blood cells.
In Drosophila, the tissue is more permeable to drugs at night, offering a possible explanation for why some medicines work better at certain times of day.
The neural nexus of the circadian clock shows signs of functional decline as mice age, providing clues as to why sleep patterns tend to change as people grow older.