Scientists image working brain cell in real time

Los Angeles Herald (IANS) Tuesday 7th February, 2012

Scientists have, for the very first time, recorded live yet detailed images of the nerve cells in the brain of a mouse.

Stefan Hell's team at the Max Planck Institute in Gottingen, Germany, used STED microscopy to explore the most intricate cerebral structures to unravel how it functions.

Captured in the previously impossible resolution of less than 70 nanometres (a nanometre is a billionth of a metre), these images have made the ultra minute structures visible which allow nerve cells to communicate with one another.

This application of STED microscopy opens up numerous new possibilities for neuroscientists to decode fundamental processes in the brain, according to a Max Planck statement.

Every moment our brain processes an enormous amount of data, with each of its 100 billion nerve cells (neurons) chatting with thousands of neighbouring nerve cells.

The entire data exchange takes place via contact sites - the synapses. Only if neurons communicate via synapses and at the right place can the brain master its complex tasks -- playing a difficult piece of piano, learning to juggle, etc.

We can learn most about these important contact sites in the brain by observing them at work. When and where do new synapses form and why do they disappear elsewhere? This is not easy to determine, since details in living nerve cells can only be observed with optical microscopes.

Due to the peculiarities of light, however, structures located closer together than 200 nanometres appear as a single blurred spot. The STED microscopy developed by Stefan Hell and his team is a groundbreaking method devised to surpass this resolution limit.

They use a simple trick: Closely-positioned elements are kept dark under a special laser beam so that they emit fluorescence sequentially one after the other, rather than simultaneously, and can therefore be distinguished.

Using this technique, Hell's team has been able to increase the resolution by approximately tenfold compared to conventional optical microscopes.

Thanks to STED microscopy, the first real-time video clips from a neuron's interior have demonstrated how tiny transmitter vesicles (assembly of molecules) migrate within the long nerve cell endings.