Coupled intra- and extracellular Ca2+ dynamics in recurrent seizure-like events.
We considered the evolution of Ca2+ oscillation dynamics in recurrent seizure-like events. Dynamic system behaviour was characterized in the state space reconstructed from intra- and extracellular [Ca2+] fluctuations simultaneously measured in cultured rat hippocampal slices under low-[Mg2+] conditions. When associated in the seizure-like event, these fluctuations occurred on a restricted set, the attractor, embedded in the full state space with less than five degrees of freedom. Instantaneous relative phase differences indicated field potential-driven phase jumps locked onto seizure-like events. To account for recurrent dynamics, calculations were performed on different extensions of a model for Ca2+ oscillation. These identified bidirectional, asymmetrical coupling of extracellular with intracellular (cytosolic, Ca2+ store, mitochondrial) Ca2+ dynamics as critical in its development.
Szilágyi
N
N
Department of Physiology and Neurobiology, Eötvös Loránd University, Múzeum krt. 4/A. H-1088 Budapest, Hungary.
Kovács
R
R
Kardos
J
J
D000818:Animals; D002118:Calcium / Q000502:physiology*; D002478:Cells, Cultured; D003600:Cytosol / Q000378:metabolism; D006624:Hippocampus / Q000502:physiology*; D066298:In Vitro Techniques; D007700:Kinetics; D008274:Magnesium / Q000494:pharmacology / Q000502:physiology; D008433:Mathematics; D008928:Mitochondria / Q000378:metabolism; D008959:Models, Neurological; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D009991:Oscillometry; D051381:Rats; D012008:Recurrence; D012640:Seizures / Q000503:physiopathology*; D013997:Time Factors
D008274:Magnesium; D002118:Calcium