J. Neurosci. 28, 6592—6606 (2008)

The brain can recover so well from a stroke that initially paralysed limbs can be moved again. Scientists have discovered how this happens at the level of individual neurons.

Timothy Murphy and Ian Winship of the University of British Columbia in Vancouver induced stroke in adult mice and used an in vivo imaging technique called two-photon microscopy to monitor the activity of individual neurons close to the site of damage.

In the first month — when paralysis is usually at its worst — they found that some neurons ditched their speciality for one particular limb and began processing information from multiple limbs. During the following month, as the affected brain region reorganized itself more permanently, those neurons re-specialized to a new single limb.