title: Small-world networks of spontaneous Ca(2+) activity.
abstract: Synchronized network activity among groups of interconnected cells is essential for diverse functions in the brain. However, most studies have been made on cellular networks in the mature brain when chemical synapses have been formed. Much less is known about the situation earlier in development. When studying neural progenitors derived from embryonic stem cells and neural progenitors from mice embryos, we found networks of gap junction coupled cells with vivid spontaneous non-random calcium (Ca(2+)) activity driven by electrical depolarization that stimulated cell growth. Network activity was revealed by single-cell live Ca(2+) imaging and further analyzed for correlations and network topology. The analysis revealed the networks to have small-world characteristics with scale-free properties. Taken together, these results demonstrate that immature cells in the developing brain organize in small-world networks that critically regulate neural progenitor proliferation.
authors.affiliation: Department of Medical Biochemistry and Biophysics; Karolinska Institutet; Stockholm, Sweden ; Department of Chemical and Systems Biology; School of Medicine; Stanford University; Stanford, CA USA.
authors.forename: Seth
authors.initials: S
authors.lastname: Malmersjö
authors.forename: Paola
authors.initials: P
authors.lastname: Rebellato
authors.forename: Erik
authors.initials: E
authors.lastname: Smedler
authors.forename: Per
authors.initials: P
authors.lastname: Uhlén
keywords: calcium signaling; gap junctions; networks; neural progenitors; stem cells