Synchronization of entorhinal cortex stellate cells
© Crotty et al; licensee BioMed Central Ltd. 2012
Published: 16 July 2012
Synchronized oscillations of large numbers of central neurons are believed to be important for a wide variety of cognitive functions, including long-term memory recall and spatial navigation. It is therefore plausible that evolution has optimized the biophysical properties of central neurons in some way for synchronized oscillations to occur.
The stellate cells in layer II of the entorhinal cortex are involved in the representation of positional information through their role as “grid cells” projecting to the place cells of the hippocampus . Both place cells and grid cells exhibit a large scale synchronized background oscillation in the theta range (8 to 12 Hz). This background oscillation is believed to be necessary for the phase coding of location within a place or grid field .
We used computational models of these cells  to investigate the relationships between the presumably genetically determined parameters of stellate cells in layer II of the entorhinal cortex and the ease with which coupled populations of these cells synchronize their intrinsic oscillations: in particular, we calculated the time it takes cells with initially randomly distributed phases to synchronize their oscillations to within one action potential width, and the metabolic energy they consume in doing so. The parameters we varied were the maximum conductances for the persistent sodium current and the hyperpolarization activated cation current, which have the most effect on the intrinsic firing frequency of the neurons.
- Hafting T, Fyhn M, Molden S, Moser MB, Moser EI: Microstructure of a spatial map in the entorhinal cortex. Nature. 2005, 436: 801-806. 10.1038/nature03721.View ArticlePubMedGoogle Scholar
- Hafting T, Fyhn M, Bonnevie T, Moser MB, Moser EI: Hippocampus-independent phase precession in entorhinal grid cells. Nature. 2008, 453: 1248-1253. 10.1038/nature06957.View ArticlePubMedGoogle Scholar
- Acker CD, Kopell N, White JA: Synchronization of strongly coupled excitatory neurons: relating network behavior to biophysics. Journal of Computational Neuroscience. 2003, 15: 71-90. 10.1023/A:1024474819512.View ArticlePubMedGoogle Scholar
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