(Adapted from Fiala and Harris, 1999.)
Varicosity |
An enlargement in a thinner dendrite associated with synaptic contacts | Retinal amacrine cells |
Filopodium  |
A long, thin protrusion with a dense actin matrix and few internal organelles | Normally only seen during development |
Simple Spine: Sessile |
Synaptic protrusions without a neck constriction
|
Pyramidal cells of cortex Cerebellar dentate nucleus |
Simple Spine: Pedunculated |
Bulbous enlargement at tip
|
Pyramidal cells of cortex Pyramidal cells of cortex Olfactory bulb granule cell |
Branched Spine |
Each branch has a unique presynaptic partner and each branch has the shape characteristics of a simple spine | CA1 pyramidal cells Granule cells of dentate gyrus Cerebellar Purkinje cells |
Claw Ending |
Synaptic protrusions at the tip of the dendrite associated with one or more glomeruli | Granule cells of cerebellar cortex and dorsal cochlear nucleus |
Brush Ending |
Spray of complex dendritic protrusions at the end of dendrite that extends into glomerulus and contains presynaptic elements | Unipolar brush cells of cerebellar cortex and dorsal cochlear nucleus |
Thorny Excrescence |
Densely lobed dendritic protrusion into a glomerulus | Proximal dendrites of CA3 pyramidal cells and dentate gyrus mossy cells |
Racemose Appendage |
Twig-like branched dendritic appendages that contain synaptic varicosities and bulbous tips | Inferior olive Relay cells of lateral geniculate nucleus |
Coralline Excrescence |
Dendritic varicosity extending numerous thin protrusions, velamentous expansions and tendrils | Cerebellar dentate nucleus Lateral vestibular nucleus |