Table 3.

Comparison of spine types

Typical mushroomThorny ExcrescenceToric
SizeSmallLargeLarge
NeckThinThinWide
Spine headLargeLargeRarely apparent
Branched?RarelyProfuselySometimes
Holes?NoNoYes
Cellular locationDendritesBase of apical dendriteSoma and dendrites
Synapses per spine∼110+10+
Axonal inputs∼11–2Up to 11
FunctionCompartmentalizationDetonationIntegration
  • The morphologies, dimensions, patterns of synaptic convergence, and known or hypothesized functions are shown for typical mushroom spines (e.g. Arellano et al., 2007, their Fig. 2) thorny excrescences (e.g. Wilke et al., 2013, their Fig. 5) and toric spines.