Photobleaching and Photoactivation techniques

photobleaching

Time lapse series of images of dendrites and spines in neurons transfected with mCherry (to highlight the morphology) and a photo-activatable GFP tagged to a synaptic protein. Using a two-photon laser, a small region (circles) is photo-activated to “light up” the protein in spines and to follow its diffusion out of the spine over time. In active neurons, this protein resides for much longer time in the synapse.