GO:0043197:   dendritic spine
A small, membranous protrusion from a dendrite that forms a postsynaptic compartment - typically receiving input from a single presynapse. They function as partially isolated biochemical and an electrical compartments. Spine morphology is variable including thin, stubby, mushroom, and branched, with a continuum of intermediate morphologies. They typically terminate in a bulb shape, linked to the dendritic shaft by a restriction. Spine remodeling is though to be involved in synaptic plasticity.