title: In vitro seizure like events and changes in ionic concentration.
abstract: BACKGROUND
  In vivo, seizure like events are associated with increases in extracellular K(+) concentration, decreases in extracellular Ca(2+) concentration, diphasic changes in extracellular sodium, chloride, and proton concentration, as well as changes of extracellular space size. These changes point to mechanisms underlying the induction, spread and termination of seizure like events.
  
  
  METHODS
  We investigated the potential role of alterations of the ionic environment on the induction of seizure like events-considering a review of the literature and own experimental work in animal and human slices.
  
  
  RESULTS
  Increasing extracellular K(+) concentration, lowering extracellular Mg(2+) concentration, or lowering extracellular Ca(2+) concentration can induce seizure like events. In human tissue from epileptic patients, elevation of K(+) concentration induces seizure like events in the dentate gyrus and subiculum. A combination of elevated K(+) concentration and 4-AP or bicuculline can induce seizure like events in neocortical tissue.
  
  
  CONCLUSIONS
  These protocols provide insight into the mechanisms involved in seizure initiation, spread and termination. Moreover, pharmacological studies as well as studies on mechanisms underlying pharmacoresistance are feasible.
authors: Institute of Neurophysiology and Neuroscience Research Center, Charité - Universitätsmedizin Berlin, Charitéplatz 1, D 10117 Berlin, Germany.
authors: Leandro Leite
authors: LL
authors: Antonio
authors: Institute of Neurophysiology and Neuroscience Research Center, Charité - Universitätsmedizin Berlin, Charitéplatz 1, D 10117 Berlin, Germany.
authors: Marlene Lulie
authors: ML
authors: Anderson
authors: Institute of Neurophysiology and Neuroscience Research Center, Charité - Universitätsmedizin Berlin, Charitéplatz 1, D 10117 Berlin, Germany.
authors: Eskedar Ayele
authors: EA
authors: Angamo
authors: Institute of Neurophysiology and Neuroscience Research Center, Charité - Universitätsmedizin Berlin, Charitéplatz 1, D 10117 Berlin, Germany.
authors: Siegrun
authors: S
authors: Gabriel
authors: Institute of Neurophysiology and Neuroscience Research Center, Charité - Universitätsmedizin Berlin, Charitéplatz 1, D 10117 Berlin, Germany.
authors: Zin-Juan
authors: ZJ
authors: Klaft
authors: Department of Anesthesiology, Charité - Univesitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany.
authors: Agustin
authors: A
authors: Liotta
authors: Institute of Neurophysiology and Neuroscience Research Center, Charité - Universitätsmedizin Berlin, Charitéplatz 1, D 10117 Berlin, Germany.
authors: Seda
authors: S
authors: Salar
authors: Department of Neurosurgery, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany.
authors: Nora
authors: N
authors: Sandow
authors: Institute of Neurophysiology and Neuroscience Research Center, Charité - Universitätsmedizin Berlin, Charitéplatz 1, D 10117 Berlin, Germany. Electronic address: Uwe.Heinemann@charite.de.
authors: Uwe
authors: U
authors: Heinemann
mesh_terms: D000200:Action Potentials; D000818:Animals; D004195:Disease Models, Animal; D006801:Humans; D007473:Ion Channels / Q000378:metabolism*; D007477:Ions; D008670:Metals / Q000378:metabolism*; D008959:Models, Neurological; D009474:Neurons / Q000378:metabolism*; D012640:Seizures / Q000503:physiopathology*
chemical_list: D007473:Ion Channels; D007477:Ions; D008670:Metals
keywords: Chronic epileptic tissue; Electrolyte changes; Human tissue; Ictogenesis; Increased seizure threshold