Dendritic Spine Features

Dendritic Spines

Image showing the four spine types and associated features. ^[1]

Flow of spine classification ^[2]

Tiny protrusions from the dendrite's membrane the spines affect the transmission properties of the signal that the dendrite receives from the synapse of an axon. The spine's two main anatomical regions are the the head and the neck. The region at the tip of the spine head is the post-synaptic densities (PSDs). ^[3] The types of spines can qualitatively be described as Stubby, Mushroom, Thin, or Branched (Bifurcated). ^[1] The Features can be summarized in the following table.

Feature	Description	Equation
dh	Diameter of the head	measured from the radius
dn	Diameter of the neck	measured from the radius
L	side length *	measured from PDS to dendrite surface
Ln	Neck length	Measured bottom of head to dendrite surface
HNR	Head to Neck Ratio
MSH	Maximum Spine Height
MSW	Maximum Spine Width

The classifications of spines can be determined by the following

Type	Description	Equation
Thin	Tall spine with narrow neck
Mushroom	Large Head
Stubby	Short- no neck
Branched	Multiple heads	h1...hi

The spines can be classified in the manner described in the flowchart^[2].

• the Side Length is also Spine Height or Distance to Surface (DTS) in some papers.

References

1. ↑ ^{1.0 1.1} Harris, K. M., F. E. Jensen, et al. (1992). "Three-dimensional structure of dendritic spines and synapses in rat hippocampus (CA1) at postnatal day 15 and adult ages: implications for the maturation of synaptic physiology and long-term potentiation." J Neurosci 12(7): 2685-705.
2. ↑ ^{2.0 2.1} Rodriguez A, Ehlenberger DB, Dickstein DL, Hof PR, Wearne SL (2008) Automated Three-Dimensional Detection and Shape Classification of Dendritic Spines from Fluorescence Microscopy Images. PLoS ONE 3(4): e1997. doi:10.1371/journal.pone.0001997
3. ↑ http://en.wikipedia.org/wiki/Dendritic_spine