A neural-glial network for modeling spreading depression in cortex
© Gibson et al; licensee BioMed Central Ltd. 2008
Published: 11 July 2008
Background and model
Spreading depression (SD) is a propagating wave of transient neuronal hyperexcitability followed by complete electrical silence that moves slowly (15–50 μm s-1) across grey matter in the central nervous system; it has been implicated in a number of brain disorders . SD involves a massive redistribution of ions (K+, Na+, Ca2+, Cl -) between intracellular and extracellular compartments. Although first described over 60 years ago, it is still not well understood . SD is accompanied by large increases in extracellular ATP, which is a principal means of transmission between astrocytes; also, ATP waves in astrocyte networks move at speeds comparable to SD [2, 3]. These facts, and other evidence , strongly suggest that astrocytes play an important role in SD.
Results and conclusion
The model accounts for the main experimental properties of SD; in particular, the speed of the wave and the accompanying changes in ion concentrations and potentials in the cells and in the extracellular medium (Figure 1 shows one example) and are in broad agreement with those observed [1, 4]. This work supports the hypothesis that SD is a result of neuron-astrocyte interactions involving the neurotransmitters glutamate and ATP. Further experimental work is now needed to justify the detailed interactions proposed by the model.
- Smith JM, Bradley DP, James MF, Huang CLH: Physiological studies of cortical spreading depression. Biol Rev. 2006, 81: 457-481. 10.1017/S1464793106007081.View ArticlePubMedGoogle Scholar
- Bennett MR, Farnell L, Gibson WG: A quantitative model of purinergic junctional transmission of calcium waves in astrocyte networks. Biophys J. 2005, 89: 2235-2250. 10.1529/biophysj.105.062968.PubMed CentralView ArticlePubMedGoogle Scholar
- Bennett MR, Buljan V, Farnell L, Gibson WG: Purinergic junctional transmission and propagation of calcium waves in spinal cord astrocyte networks. Biophys J. 2006, 91: 3560-3571. 10.1529/biophysj.106.082073.PubMed CentralView ArticlePubMedGoogle Scholar
- Martins-Ferreira H, Nedergaard M, Nicholson C: Perspectives on spreading depression. Brain Res Rev. 2000, 32: 215-34. 10.1016/S0165-0173(99)00083-1.View ArticlePubMedGoogle Scholar
- Bennett MR, Farnell L, Gibson WG: Origins of blood volume change due to glutamatergic synaptic activity at astrocytes abutting on arteriolar smooth muscle cells. J Theor Biol. 2008, 250: 172-185. 10.1016/j.jtbi.2007.08.024.View ArticlePubMedGoogle Scholar
- Dronne M-A, Boissel J-P, Greiner E: A mathematical model of ion movements in grey matter during a stroke. J Theor Biol. 2006, 240: 599-615. 10.1016/j.jtbi.2005.10.023.View ArticlePubMedGoogle Scholar
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