Fig. 4.

Changes in EGFP diffusion during movement in individual spines. A–C, Measurements of diffusional coupling in spines whose necks stayed the same length (A), shortened (B), or grew longer (C). Middle,Right, Images of the spine at the first time point (middle) and at the second time point (right). White lines trace the length of the neck. Left, The EGFP fluorescence recoverytraces. Solid traces correspond to the recoveries obtained at the first time point (middle), whereas stippled traces correspond to those obtained at the second time point (right). The change in time constants for the spines shown is as follows: from 130 to 135 msec (A), from 380 to 170 msec (B), and from 260 to 480 msec (C). Scale bars, 1 μm.