A study released in July dispelled some of the mystery surrounding sudden infant death syndrome, or SIDS, which kills 2,500 babies a year in the United States.
Jan-Marino Ramirez, a biologist at the University of Chicago, figured out how two aspects of SIDS fit together. First, a child who has the syndrome cannot gasp air. Thus, if a pillow blocks her airway and her brain begins to starve for oxygen, she can’t kick-start her breathing back to normal. Second, in a SIDS child, the neurotransmitter called serotonin often doesn’t bind properly to brain cells. In experiments with laboratory mice, Ramirez and his colleagues distinguished two groups of pacemaker neurons that govern breathing. One group regulates normal breathing; the other group regulates gasping. They found that serotonin regulates the sodium channels that drive the gasping cells. Moreover, problems in sodium channels play a role in epilepsy and heart disorders—both common in ...
