Functional mapping of single spines in cortical neurons in vivo

It is notoriously difficult to determine how individual neurons integrate the inputs from the many incoming dendritic signals in live animals. Arthur Konnerth and colleagues use a new variant of the two-photon imaging technique to visualize sound-evoked activity in the spines of cortical neurons at single-synapse resolution in vivo. They find that individual spines are highly tuned for specific tones and that even neighbouring spines on the same dendrite can be tuned to different frequencies. This work establishes a new method for the mapping of functionally defined single synapses in the living brain.