Channel Hopping

Addiction is a complex physiological phenomenon. And smoking is among the most difficult habits to kick. Nicotine affects tiny protein 'tunnels' – known as ion channels – in the membranes of our nerve cells, producing a combination of stimulant and relaxant effects on the body. By binding to specific channels, it causes them to swing open, allowing ions (molecular messengers) to flow into the cell. This triggers the production of neurotransmitters including acetylcholine. Acetylcholine acts on another channel simultaneously prompting contraction of skeletal muscle and relaxation of heart. Similar channels are found in the cells of animals, plants and even bacteria. Pictured above is a computer simulation of a channel from the bacterium Erwinia chrysanthemi. Reconstructed from crystallography experiments the image shows how individual atoms are arranged in the protein. Being simpler than its human counterpart the bacterial channel provides a model system to better understand how these channels work.

Written by Kat Arney

Kat Arney

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Dr Kat Arney is an award-winning science writer, broadcaster and public speaker, and is the founder and Creative Director of First Create The Media.

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• Raimund Dutzler
• Department of Biochemistry, University of Zurich, Switzerland
• Originally published under Creative Commons (CC-BY 2.0)
• Published in PLoS Biology