Question: What do you mean by cells talking to themselves?

Helen Tunbridge answered on 18 Jun 2013:

Cells can communicate with each other in different ways: one cell might release a chemical which the other receives on its surface, like someone sending a letter. Another method is by the two cells actively touching each other, like people shaking hands. In both cases, a receptor on the receiving cell’s surface gets activated, and can let the inside of the cell know what has happened on the outside. In reality this is an awful lot more complicated than I’ve explained it, with lots of different molecules being involved.

For example I research immune cells, so I look at two kinds of white blood cells: B cells and T cells. B cells can detect foreign things like bits of virus, stick it on their membrane and then show or ‘present’ it to T cells, so that the T cells know that the body is infected and they need to change in order to get rid of the infection.