Salt Signals

Our cells, like those of other complex organisms, communicate with one another using electrical messages sent through the biological email network known as the nervous system. Generating the electrical charge for these messages requires the protein 'gatekeeper' molecules located in our cell membranes to let a different amount of positive and negatively charged salt ions pass through them. A charge differential then develops between ions inside and outside the cell. When this reaches a certain level, a high-speed electrical impulse is released along a nerve fibre. When the salt concentration inside the cell is high, similar amounts of positive (purple) and negative (green) ions may pass through the protein gate (bottom two images). At lower concentrations (top two images), the protein gate lets more negative than positive ions pass through, and a charge differential builds up across the cell membrane.

Written by Andrew Purcell

Andrew Purcell

Writer

As a science journalist Andrew is currently online producer for New Scientist. Former editor of I, Science magazine at Imperial College, he also won The Science Challenge 2011.

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• Martine Prévost
• Structure et Fonction des Membranes Biologiques, Université Libre de Bruxelles, Brussels, Belgium
• Martine Prévost
• Published in PLoS One