https://phys.org/news/2018-11-scientists-minimally-invasive-brain-probe.html

"We are very excited to see our technology making its first steps toward practical applications in neuroscience," says Dr. Sergey Turtaev from Leibniz-IPHT, lead author of the paper.

"For the first time, we have shown that it is possible to examine deep brain regions of a living animal model in a minimally invasive way and to achieve high-resolution images at the same time," says IPHT scientist Dr. Ivo T. Leite. Sergey and Ivo work in the research group that developed the holographic method for imaging through a single fibre. Using this approach, the research team obtained images of brain cells and neuronal processes in the visual cortex and hippocampus of living mice with resolution approaching one micrometre. Detailed observations within these areas are crucial for research into sensory perception, memory formation and severe neuronal diseases such as Alzheimer's. Current investigation methods are strongly invasive, such that it is not possible to observe neuronal networks in these inner regions at work without massive destruction of the surrounding tissue—endoscopes comprising hundreds of optical fibres are too large to penetrate such sensitive brain regions, while the neuronal structures are too tiny to be visualised by non-invasive imaging methods such as magnetic resonance imaging (MRI).