title: Different Ca2+ dynamics between isolated hippocampal pyramidal cells and dentate granule cells.
abstract: The hippocampal formation contains a variety of neuronal types. The principal neurons are granule cells in the dentate gyrus and pyramidal cells in Ammon's horn. These two neuron types show distinct cell morphology and display a different vulnerability to ischemic injury or various neurotoxins. In order to illustrate the difference in the pathophysiological properties of these neurons, we established a method for separately culturing granule cells and pyramidal cells. They were prepared from the dentate gyrus and Ammon's horn of 3-day-old Wistar rat pups and maintained for 7-9 days in culture. After transient exposure to N-methyl-D-aspartate or glutamate, both the cultured neuron populations displayed somatic Ca(2+) transients with similar amplitudes, but the subsequent recovery to baseline was about twice as fast in granule cells than in pyramidal cells. Similar results were obtained for K(+) depolarization-induced Ca(2+) elevation, suggesting that the relatively rapid Ca(2+) clearance in granule cells is independent of Ca(2+) influx pathways. The present study provides the first evidence for a difference in Ca(2+) dynamics and homeostasis between granule and pyramidal cells and may represent a cellular basis for the differential vulnerability of hippocampal neurons.
authors.affiliation: Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Baba
authors.forename: Maki K
authors.initials: MK
authors.lastname: Yamada
authors.forename: Nobuyoshi
authors.initials: N
authors.lastname: Nishiyama
authors.forename: Norio
authors.initials: N
authors.lastname: Matsuki
authors.forename: Yuji
authors.initials: Y
authors.lastname: Ikegaya
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D018891:Dentate Gyrus / Q000166:cytology / Q000378:metabolism*; D006624:Hippocampus / Q000166:cytology / Q000378:metabolism; D017966:Pyramidal Cells / Q000166:cytology / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D002118:Calcium