Researchers have devised a new imaging technique for peering deep inside the brains of mice to monitor neurons in real-time. The method, which, unlike standard approaches, allows investigators to track the same location in the brain for months, should offer new insights into cancer, neurological disease and trauma-induced conditions.

With the new method, “imaging is possible over a very long time without damaging the region of interest,” said Juergen Jung, a microscopist at Stanford University in California and a co-author of the study published online this week in Nature Medicine, in a press release.

The technology relies on miniature glass tubes, about half the width of a grain of rice, that are implanted into the deep brain of anaesthetized mice. A tiny optical instrument called a microendoscope is then threaded inside the tube, allowing researchers to return to exactly the same brain location — down to the level of an individual cell — repeatedly over weeks or months.

As a proof of principle, the Stanford team tracked the growth of glioma brain cancer cells. The following video shows a three-dimensional stack of 220 images each taken about 3 micrometers apart to reveal blood vessel growth in the hippocampus of wild-type mice.