title: Synchronization of action potentials during low-magnesium-induced bursting.
abstract: The relationship between mono- and polysynaptic strength and action potential synchronization was explored using a reduced external Mg(2+) model. Single and dual whole cell patch-clamp recordings were performed in hippocampal cultures in three concentrations of external Mg(2+). In decreased Mg(2+) medium, the individual cells transitioned to spontaneous bursting behavior. In lowered Mg(2+) media the larger excitatory synaptic events were observed more frequently and fewer transmission failures occurred, suggesting strengthened synaptic transmission. The event synchronization was calculated for the neural action potentials of the cell pairs, and it increased in media where Mg(2+) concentration was lowered. Analysis of surrogate data where bursting was present, but no direct or indirect connections existed between the neurons, showed minimal action potential synchronization. This suggests the synchronization of action potentials is a product of the strengthening synaptic connections within neuronal networks.
authors.affiliation: Department of Chemical Engineering, University of Virginia, Charlottesville, Virginia; and.
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Johnson
authors.affiliation: Department of Chemical Engineering, University of Virginia, Charlottesville, Virginia; and.
authors.forename: John L
authors.initials: JL
authors.lastname: Hudson
authors.affiliation: Departments of Neurology and Neuroscience, University of Virginia School of Medicine, Charlottesville, Virginia jk8t@virginia.edu.
authors.forename: Jaideep
authors.initials: J
authors.lastname: Kapur
mesh_terms: D000200:Action Potentials; D000818:Animals; D002478:Cells, Cultured; D006624:Hippocampus / Q000502:physiology*; D008274:Magnesium; D017966:Pyramidal Cells / Q000502:physiology*; D017207:Rats, Sprague-Dawley; D013569:Synapses; D009435:Synaptic Transmission
chemical_list: D008274:Magnesium
keywords: action potential; dual whole cell patch-clamp; hippocampal culture; synchronization