Tunnelling to the heart of cell communication

Multicellular existence is collaborative. Our cells are in constant communication, checking out one another’s state and sending signals to modulate or moderate the behaviour of neighbours. The usual textbook story identifies three means of communication. Chemically specific signals emitted by one cell, such as hormones or neurotransmitters, might be registered by receptors on the surface of another; electrical signalling, like that among neurons, is common to most cells via channel proteins called gap junctions; and many cells will respond to mechanical signals using mechanosensitive ion channels. Cells can also send out packages called exosomes, lipid vesicles that bubble off from the cell membrane.