Y Liu

In the orchestra of the worm Caenorhabditis elegans, which has 302 neurons, the protein NHR-49 was long cast as a conductor who runs nothing but the fat warehouse. But a new experiment shows that this conductor can walk onstage without a fat score in hand.

Every heartbeat sends a wave through the cerebral arteries that not only pushes blood but also briefly inflates the vessel. The arterial wall, like a tightly stretched rubber tube, passes that motion to the neighboring brain tissue, and the brain pulses ever so slightly in time with the heartbeat.

Old age begins with familiar things getting stiffer: skin, joints, blood vessel walls. The intestine is no exception. Its muscular coat accumulates collagen with age, and the tissue stops being elastic. This used to be seen as simply a consequence of wear and tear, but a new study shows that stiffness itself is a command that makes smooth muscle cells forget their job.