Cells talk to their neighbors before making a move

To decide whether and where to move in the body, cells must read chemical signals in their environment. Individual cells do not act alone during this process, two new studies on mouse mammary tissue show. Instead, the cells make decisions collectively after exchanging information about the chemical messages they are receiving.

"Cells talk to nearby cells and compare notes before they make a move," says Ilya Nemenman, a theoretical biophysicist at Emory University and a co-author of both studies, published by the Proceedings of the National Academy of Sciences (PNAS). The co-authors also include scientists from Johns Hopkins, Yale and Purdue.

The researchers discovered that the cell communication process works similarly to a message relay in the telephone game. "Each cell only talks to its neighbor," Nemenman explains. "A cell in position one only talks to a cell in position two. So position one needs to communicate with position two in order to get information from the cell in position three."

And like the telephone game -- where a line of people whisper a message to the person next to them -- the original message starts to become distorted as it travels down the line.

The researchers found that, for the cells in their experiments, the message begins to get garbled after passing through about four cells, by a factor of about three.