Many types of neurons receive synaptic inputs on dendritic spines which are short protrusions of membrane composed of a bulbous “head” connected to the dendrite by a thin “stem” or “neck” (Yuste 2010). Although spines are typically small in size, they occur in high densities along dendrites and may compose 40–60 % of the total dendritic surface area. There are two straightforward methods for including spines in computational models of neurons without representing every spine explicitly.
Spines are widely regarded to serve a biochemical function by providing an isolated compartment where highly localized calcium signals and subsequent reactions can occur. An electrical function was initially proposed by Rall who showed that the steady-state attenuation of a signal from the spine head to the dendrite could be expressed as VSH/VBI = 1 + RSS/RBI, where VSH and VBI are the voltages at the spine head and dendrite, respectively; RSSis the spine stem...
- Yuste R (2010) Dendritic spines. MIT Press, Cambridge, MAGoogle Scholar