title: Distinct expressions for synaptic potentiation induced by calcium through voltage-gated calcium and N-methyl-D-aspartate receptor channels in the hippocampal CA1 region.
abstract: Brief elevation in postsynaptic calcium in hippocampal CA1 neurons leads to prolonged changes in synaptic strength. The calcium may enter the postsynaptic neuron via different routes, such as voltage-gated calcium channels or glutamate receptor channels of N-methyl-D-aspartate type, and/or be released from intracellular stores. The manner in which the synapse is altered, leading to the expression of an enhanced/depressed synaptic strength, is still unclear. The present study, performed using whole-cell recording from CA1 pyramidal cells of three- to five-week-old guinea-pigs, shows that postsynaptic depolarization alone, allowing for calcium influx through voltage-gated calcium channels, leads to a synaptic potentiation characterized by an altered time-course of the evoked excitatory synaptic response, an unaltered coefficient of variation of that response and a decreased paired-pulse facilitation likely related to a postsynaptic mechanism. These characteristics contrasted with those of long-term potentiation induced via activation of N-methyl-D-aspartate receptor channels, where the time-course was unaltered, the coefficient of variation was decreased and no change in paired-pulse facilitation was observed. Synapses can thus have mechanistically separate, but co-existent, potentiations of synaptic transmission initiated from separate sources for postsynaptic calcium.
authors.affiliation: Department of Physiology and Pharmacology, Göteborg University, Sweden.
authors.forename: H X
authors.initials: HX
authors.lastname: Chen
authors.forename: E
authors.initials: E
authors.lastname: Hanse
authors.forename: M
authors.initials: M
authors.lastname: Pananceau
authors.forename: B
authors.initials: B
authors.lastname: Gustafsson
mesh_terms: D000818:Animals; D002118:Calcium / Q000494:pharmacology / Q000502:physiology*; D015220:Calcium Channels / Q000502:physiology*; D005071:Evoked Potentials / Q000187:drug effects / Q000502:physiology; D006168:Guinea Pigs; D006624:Hippocampus / Q000502:physiology*; D066298:In Vitro Techniques; D017774:Long-Term Potentiation / Q000187:drug effects / Q000502:physiology*; D009473:Neuronal Plasticity / Q000187:drug effects / Q000502:physiology; D017966:Pyramidal Cells / Q000187:drug effects / Q000502:physiology*; D016194:Receptors, N-Methyl-D-Aspartate / Q000187:drug effects / Q000502:physiology*; D013569:Synapses / Q000187:drug effects / Q000502:physiology*
chemical_list: D015220:Calcium Channels; D016194:Receptors, N-Methyl-D-Aspartate; D002118:Calcium