(Above) Video of the mouse's brain operating (via Max Planck Institute of Biophysical Chemistry)
Many methods have been used to study and understand the brain. These methods have limitations that restrict how well the micro structures can be seen and how they behave in real time. Now, scientists at the Max Planck Institute of Biophysical Chemistry in Gottingen, Germany, have developed a new nanoscopic scanning system to observe previously impossible resolution of the structures of the living brain of a mouse.
To achieve this unprecedented resolution of live brain images, the team developed a stimulated emission depletion (STED) fluorescence microscope. Images come from a 1.3 numerical aperture lens which focuses an 80 MHz sequence of 70 ps pulses of 488 nm wavelength light through a glass-sealed hole located on the skull of the mouse.
The mice are given an extra gene that causes a yellow glow to the cells of the brain which are stimulated and detected by the STED microscope. This allowed researchers to view the living brain of a mouse with a resolution of 70 nanometers.
The STED microscope focused on the cerebral cortex of the mouse’s brain, an area that controls movement. The neurons and dendrites where observed as they move to make connections with neighboring cells, perhaps capturing the process of the mouse thinking. A challenge in achieving the high resolution of the neuron structure was to minimize vibrations. For this reason, the mouse was anaesthetized and even it’s vital functions were performed artificially. The resulting images were also filtered using emerging super resolution techniques.
This type of technology could enable researchers to diagnose connectivity problems that happen in mental disorders like Parkinson’s or dementia, by creating these disorders in the mice. Further developments of STED microscopes could penetrate deeper into the brain and implants could one day provide images of a conscious animal’s brain, functioning in real time.
Animals certainly carry a heavy burden in science. Engineering On Friday's take on the subject.