Lyndsey M Kirk, The University of Texas at Austin, Austin, Texas, USA
Kristen M Harris, The University of Texas at Austin, Austin, Texas, USA
Published online: November 2016
Dendritic spines are small protrusions from dendrites that host the majority of excitatory synapses in the central nervous
system. Structurally, excitatory synapses located on dendritic spines are asymmetric, with a presynaptic bouton that contains
round clear vesicles apposed to a postsynaptic density where glutamate receptors are anchored. Spines form biochemical compartments
that can isolate activated signalling pathways that occur at one synapse from those at other synapses, thereby providing a
way to enhance the specificity of connections between neurons in the brain. Structural changes of dendritic spines in response
to stimulation facilitate changes in synaptic strength, and these changes are likely to underlie important higher brain functions
such as learning and memory. Dysregulation of spine morphology is seen in several neurological disorders such as Alzheimer's
disease and fragile X syndrome.
- Spines are the primary site of excitatory synapses.
- Smooth endoplasmic reticulum can form complex structures localized to large spines.
- The cytoskeleton of spines is mostly composed of actin.
- Trans‐synaptic adhesion molecules as well as proteins secreted from astroglia help stabilise synapses.
- Spines can act as small biochemical compartments.
- Spine structure is responsive to activity.
Keywords: brain; neuron; dendrite; synapse; ultrastructure; plasticity; spine
Bell ME, Bourne JN, Chirillo MA, et al. (2014) Dynamics of nascent and active zone ultrastructure as synapses enlarge during long‐term potentiation in mature hippocampus. The Journal of Comparative Neurology 522: 3861–3884.
Bourne JN and Harris KM (2010) Coordination of size and number of excitatory and inhibitory synapses results in a balanced structural plasticity along mature hippocampal CA1 dendrites during LTP. Hippocampus 21: 354–373.
Bourne JN and Harris KM (2012) Nanoscale analysis of structural synaptic plasticity. Current Opinion in Neurobiology 3: 372–382.
Buffington SA, Huang W and Costa‐Mattioli M (2014) Translational control in synaptic plasticity and cognitive dysfunction. Annual Review of Neuroscience 37: 17–38.
Cao G and Harris KM (2014) Augmenting saturated LTP by broadly spaced episodes of theta‐burst stimulation in hippocampal area CA1 of adult rats and mice. Journal of Neurophysiology 112: 1916–1924.
Singh SK, Stoqsdill JA, Pulimood NS, et al. (2016) Astrocytes assemble thalamocortical synapses by bridging NRX1α and NL1 via hevin. Cell 164: 183–196.
Watson DJ, Ostroff L, Cao G, et al. (2016) LTP enhances synaptogenesis in the developing hippocampus. Hippocampus 26 (5): 560–576.
Bailey CH, Kandel ER and Harris KM (2015) Structural components of synaptic plasticity and memory consolidation. Cold Spring Harbor Perspectives in Biology 7 (7): a021758.
Dzyubenko E, Gottschling C and Faissner A (2016) Neuron‐Glia interactions in neural plasticity: contributions of neural extracellular matrix and perineuronal nets. Neural Plasticity 2016: Article ID 5214961.
Granger AJ and Nicoll RA (2013) Expression mechanisms underlying long‐term potentiation: a postsynaptic view, 10 years on. Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences 369 (1633): 20130136.
Harris KM and Stevens JK (1988) Dendritic spines of rat cerebellar Purkinje cells: serial electron microscopy with reference to their biophysical characteristics. Journal of Neuroscience 8: 4455–4469.
Harris KM and Kater SB (1994) Dendritic spines: cellular specializations imparting both stability and flexibility to synaptic function. Annual Review of Neuroscience 17: 341–371.
Harris KM and Stevens JK (1989) Dendritic spines of CA1 pyramidal cells in the rat hippocampus: serial electron microscopy with reference to their biophysical characteristics. Journal of Neuroscience 9: 2982–2997.
Nimchinsky EA, Sabatini BL and Svoboda K (2002) Structure and function of dendritic spines. Annual Review of Physiology 64: 313–353.
Peters A, Palay SL and deF Webster H (1991) The Fine Structure of the Nervous System: Neurons and Their Supporting Cells, 3rd edn. New York: Oxford.
Sorra KE and Harris KM (2000) Overview on the structure, composition, function, development, and plasticity of hippocampal dendritic spines. Eichenbaum HB (ed.) with Harris KM and Sorra KE (special issue eds) Dendritic Spines of the Hippocampus. Hippocampus 10: 501–511.
Stuart G, Spruston N and Hausser M (eds) (2001) Dendrites. Oxford: New York.