The Role of bI-Spectrin in Dendritic Spines Figure 5. The ABD of bI-spectrin decreases the morphological plasticity of dendritic spines. A, Time-lapse images in control saline of GFP fluorescence in a single spine from a CA1 pyramidal neuron expressing either GFP alone (upper row) or GFP together with the ABD of bI-spectrin (lower row). Rapid, ongoing changes in the shape of the spine head occurred in spines expressing GFP alone, but not in spines expressing both GFP and the ABD of bI-spectrin. Scale bar = 1 mm; time in sec. B, Changes in spine head diameter in the spines from A were plotted over time. Spines expressing GFP exhibited more spontaneous morphing, compared to A spine expressing the ABD of bI-spectrin, regardless of whether NMDARs and AMPARs were active. C, Group data showing the variance of spine head diameter in neurons expressing GFP alone or the ABD of bI-spectrin in the PLoS ONE | www.plosone.org 9 January 2011 | Volume 6 | Issue 1 | e16197