Alyssa Danigelis writes in news.discovery.com about a group if scientists for the first time ever seeing through a window into a brain. They installed a window into a mouse’s brain and observed a neuron in action.
“You can look into the brain and see a true neuron in action,” said physicist Stefan Hell, who leads the Max Planck Institute of Biophysical Chemistry’s Department of NanoBiophotonics in Germany.
In the 1990’s Hell invented a super-resolution “stimulated emission depletion” or STED microscope that can distinguish features in living samples down to 70 nanometers which is 4 times beyond what was believed to be the physical limit.
An electron microscope shows great detail but only on dead cells. The STED microscope can show us live cells in action. Here’s how they did it in Germany.
They took a mouse and altered it genetically so that its neurons produced a fluorescent agent. While the mouse was under anesthesia, they opened its skull, took out a part of the bone and replaced it with a glass window. They attached the microscope’s lens on top of the window and acting like a precise spotlight on the upper layer of the live brain, the microscope picked up the fluorescent neurons which were essentially glowing in the dark. Amazingly, the mouse survived the entire procedure.
Danigelis reports that Hell describes “Little protrusions with thin necks and a cup-like shape at the end can be seen on the neurons. These ‘dendritic spines’ are the input, the place where a neuron receives signals from a
Hell does not intend to make a window for human brains. He hopes that neuroscientists will use his team’s methods for learning more about the functions of the brain which are poorly understood and he hopes that scientists will study synaptic malfunctions of live animal brains to advance research in potential treatments. As physicists, he and his team will work to create sharper images.
Neurobiologist Bill Betz, professor and chair of physiology and biophysics at the University of Colorado School of Medicine, studies synapses and notes that all psychiatric medicine works on synapses. He owes a debt to Hell and his STED microscope. He points out that “Hell” in German means “bright.”
Columbia University biology professor Rafael Yuste’s lab looks into the cerebral cortex, the part of the brain that deals with perception, learning and memory. In 1999′ together with Andrew Matus’s group, they discovered how dendritic spines move. He would like Hell and his team of physicists to figure out a way to see deeper than the top layer of the brain as is currently the case. He has no doubt that Hell is up to the challenge.
*Image from news.discovery.com
© Max Planck Institute for Biophysical Chemistry, Goettingen