"... In this work, we extend previous modeling studies  by combining a model for activity-dependent spine density with one for
calcium-mediated spine stem restructuring.
... Additional equations characterize the change in spine density along
the dendrite, the current balance equation for an individual spine
head, the change in calcium concentration in the spine head, and the
dynamics of spine stem resistance.
We use computational studies to investigate the changes in spine
density and structure for differing synaptic inputs and demonstrate
the effects of these changes on the input-output properties of the
Crook SM, Dur-E-Ahmad M, Baer SM (2007) A model of activity-dependent changes in dendritic spine density and spine structure. Math Biosci Eng 4:617-31 [PubMed]