chemical signals

(Vanderbilt University) Scientists have detected previously unnoticed chemical signals that individual cells in the immune system use to communicate with each other over short distances.

The signals the researchers detected originated in dendritic cells -- the sentinels of the immune system that do the initial detection of microscopic invaders -- and was received by nearby T-cells, which play a number of crucial roles in the immune system, including coordination of attacks on agents that cause disease or infection.

Many animal species detect and avoid predators by smell, but this ability has been largely overlooked in the study of birds, since it was traditionally thought that they did not make use of this sense.

However, it has now been discovered that birds are not only capable of discerning their enemies through chemical signals, but that they also alter their behavior depending on the perceived level of risk of predation.

Researchers have made an important step towards the use of adult stem cells to repair damaged tissue. University of Manchester scientists report that they have uncovered a messaging system that instructs adult stem cells to contribute to tissue repair in response to chemical signals in the body.

n a finding that could provide controlled motion in futuristic nanomachines used for drug delivery, fuel cells, and other applications, researchers report that chemical signaling between synthetic microcapsules can trigger and direct movement of these capsules.

Researchers theorize that synthetic capsules can communicate with each other by physically shuffling chemical signals from capsule to capsule, much like passing water through a fireman's bucket brigade.

Scientists recently suggested that this same signaling process also appears capable of sending cues to direct cell movement.