title: Both survival and development of spontaneously active rat hypothalamic neurons in dissociated culture are dependent on membrane depolarization.
abstract: Suppression of endogenous electrical activity was found to have an adverse effect on the survival and bioelectric development of dissociated, embryonic rat hypothalamic neurons in long-term culture. Cultures were treated during the first two weeks in vitro with tetrodotoxin (TTX), a selective blocker of voltage-gated sodium channels, alone and in combination with high extracellular KCl ([K+]o), a membrane depolarizer. Neuron survival was assessed through cell counting experiments, while the development of spontaneous electrical activity was examined with extracellular, patch-electrode recordings. TTX caused both a decrease in cell survival and a decrease in spontaneously active cells; concurrent treatment with K+ protected cells from the adverse effects of TTX. K+ treatment alone increased the fraction of spontaneously active neurons without significantly affecting cell survival. When taken together, these results suggest that the long-term survival of active cells depends on continual membrane depolarization. From these observations, we conclude that there exists two populations of neurons: the electrically active population, whose survival is sensitive to electrical activity, and the quiescent population, whose survival is not.
authors.affiliation: Department of Pharmacology, UMDNJ-Robert Wood Johnson Medical School, Piscataway, NJ.
authors.forename: D S
authors.initials: DS
authors.lastname: Ling
authors.forename: R E
authors.initials: RE
authors.lastname: Petroski
authors.forename: H M
authors.initials: HM
authors.lastname: Geller
mesh_terms: D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D002470:Cell Survival / Q000502:physiology*; D004594:Electrophysiology; D007031:Hypothalamus / Q000187:drug effects / Q000502:physiology*; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D011189:Potassium Chloride / Q000494:pharmacology; D051381:Rats; D013779:Tetrodotoxin / Q000494:pharmacology
chemical_list: D013779:Tetrodotoxin; D011189:Potassium Chloride