For the first time, scientists have been able to watch neurons within the brain of a living animal change in response to experience.

The researchers at MIT’s Picower Institute implanted transparent cranial windows over the primary visual cortex, allowing them to monitor over time the expression of proteins in the brains of live mice. They used two-photon microscopy (so-called because it uses two infrared photons to emit fluorescence in tissue), which allows imaging of living tissue up to 1 millimeter deep.

Source: MIT