title: Voltage-sensitive calcium channels mediate calcium entry into cultured mammalian sympathetic neurons following neurite transection.
abstract: Calcium ion entry following mechanical neurite transection was examined in cultured sympathetic neurons loaded with the Ca2+ indicator fluo-3. Neurite transection produced a rapid [Ca2+]i rise in the cell soma which preceded any [Ca2+]i rise in the neurite (n = 30). Blocking sodium channels with tetrodotoxin had no effect on the Ca2+ rise, but inactivating voltage-sensitive Ca2+ channels by bath-applying 140 mM potassium prior to the transection, and the simultaneous application of nimodipine and omega-conotoxin GVIA, blockers of L-type and N-type Ca2+ channels, respectively, considerably attenuated the Ca2+ rise in the soma and neurites. These data contradict the intuitive hypothesis that Ca2+ entry following mechanical neurite transection occurs via non-specific influx pathways produced by cell-membrane disruption and provide direct evidence in mammalian neurons that immediate, traumatically-induced, increases in neuronal [Ca2+]i are amenable to pharmacological manipulation.
authors.affiliation: Department of Applied Cell Biology, Technical University of Mannheim, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Sattler
authors.forename: M
authors.initials: M
authors.lastname: Tymianski
authors.forename: I
authors.initials: I
authors.lastname: Feyaz
authors.forename: M
authors.initials: M
authors.lastname: Hafner
authors.forename: C H
authors.initials: CH
authors.lastname: Tator
mesh_terms: D000818:Animals; D001930:Brain Injuries / Q000378:metabolism* / Q000473:pathology; D002118:Calcium / Q000378:metabolism*; D002121:Calcium Channel Blockers / Q000494:pharmacology; D015220:Calcium Channels / Q000502:physiology*; D002478:Cells, Cultured; D008564:Membrane Potentials / Q000187:drug effects; D016501:Neurites / Q000187:drug effects / Q000502:physiology*; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D009553:Nimodipine / Q000494:pharmacology; D010455:Peptides / Q000494:pharmacology; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D017783:Superior Cervical Ganglion / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D013779:Tetrodotoxin / Q000494:pharmacology; D020866:omega-Conotoxin GVIA
chemical_list: D002121:Calcium Channel Blockers; D015220:Calcium Channels; D010455:Peptides; D013779:Tetrodotoxin; D009553:Nimodipine; D020866:omega-Conotoxin GVIA; D011188:Potassium; D002118:Calcium