As planktonic organisms the larvae of the marine annelid Platynereis swim freely in the open water. They move by activity of their cilia, thousands of tiny hair-like structures forming a band along the larval body and beating coordinately. With changing environmental conditions the larvae swim upward and downward to their appropriate water depth. Scientists of the Max Planck Institute for Developmental Biology in Tübingen, Germany have now identified some signalling substances in the larval nervous system regulating swimming depth of the larvae. These substances influence the ciliary beating and thus hold the larvae in the preferred water depth. The scientists discovered a very simple circuitry of nerve cells underlying this regulation, reflecting an early evolutionary state of the nervous system.

Scientists have successfully demonstrated that they can build some of the basic components for digital devices out of bacteria and DNA, which could pave the way for a new generation of biological computing devices, in research published today in the journal Nature Communications.

This is an electron microscope image of two crawling worm sperm magnified ~5,000X. For better and for worse, human health depends on a cell's motility –– the ability to crawl from place to place. In every human body, millions of cells –are crawling around doing mostly good deeds ––– though if any of those crawlers are cancerous, watch out.