Living Mouse Brain Neurons Captured in High Detail

Researchers at the Max Planck Institute for Biophysical Chemistry in Göttingen, Germany, have visualized for the first time the finest details of neurons in the brains of a living mouse.  To accomplish this a new imaging technique, called STED was used.   In the image above, the new gated STED technique, which will widen applications in medicine by lowering the photon flux required to produce super-resolution images, is being commercialized by Leica Microsystems.

The scientists, led by Stefan Hell, have taken a decisive step towards unraveling the finest structures of the brain to reveal how it works.

Using the Stimulated Emission Depletion (STED) microscopy technique developed by Hell, the scientists have made ​​visible the tiny structures used by neurons to communicate, with unprecedented resolution of less than 70 nanometers. This application of STED microscopy to decipher basic processes in the brain opens new paths to neurobiology studies, such  as dementia and clinical applications.

"With our STED microscope, we see even the very fine branches of nerve cells in the brain of a living mouse sharply, sitting at which the synapses. At the high resolution of 70 nanometers, we can identify these so-called spinous processes, with their mushroom-or button-shaped bulges significantly, "says Hell. They are the sharpest images yet of these elementary points of contact of the brain circuitry. 


The movie spans a 20 to 30 minute period, during which a live mouse was anaesthetised. The spines physically move and wobble at the top and base as they form and break connections with neighbouring spines. "There are always connections breaking and forming and it's the natural movement of the spine," says Willig. "It may be the mouse thinking".

"To make them visible, we genetically engineered mice that produce in their nerve cells, large amounts of a yellow fluorescent protein. This protein migrates in all branches of the nerve cell, even in the smallest, finest structures, "explains Katrin Willig, junior researcher in the Department of NanoBiophotonics Hell. The genetically altered mice derived from a breeding group of Frank Kirchhoff at the Max-Planck-Institute for Experimental Medicine. Pictures of nerve cells at a distance of seven or eight minutes the scientists revealed something surprising: The spinous processes can move and change their shape. "The super-hot live recordings in the future could even show how specific proteins are located at the contact points," said Light. With such an ever more detailed images of structures in the brain, the team will help to elucidate the structure and function of synapses at the molecular level.

Neurons have been captured sending and receiving signals in high resolution for the first time, essentially showing the brain in action.

To make the tiniest anatomical details of neurons visible, the researchers used optogenetics to give mice an extra gene that generates a yellow glow. When their brains were viewed with a special microscope through a glass-sealed window in the skull, the synapses in neurons lit up.

Check this for more: First brain movie captures a mouse thinking (New Scientist TV)