title: Prior activation of inositol 1,4,5-trisphosphate receptors suppresses the subsequent induction of long-term potentiation in hippocampal CA1 neurons.
abstract: We investigated the role of inositol 1,4,5-trisphosphate receptors (IP3Rs) activated by preconditioning low-frequency afferent stimulation (LFS) in the subsequent induction of long-term potentiation (LTP) in CA1 neurons in hippocampal slices from mature guinea pigs. Induction of LTP in the field excitatory postsynaptic potential or the population spike by the delivery of high-frequency stimulation (HFS, a tetanus of 100 pulses at 100 Hz) to the Schaffer collateral-commissural pathway to CA1 neuron synapses was suppressed when group I metabotropic glutamate receptors (mGluRs) were activated prior to the delivery of HFS. LTP induction was also suppressed when CA1 synapses were preconditioned 60 min before HFS by LFS of 1000 pulses at 1 Hz and this effect was inhibited when the test stimulation delivered at 0.05 Hz was either halted or applied in the presence of an antagonist ofN-methyl-d-aspartate receptors, group I mGluRs, or IP3Rs during a 20-min period from 20 to 40 min after the end of LFS. Furthermore, blockade of group I mGluRs or IP3Rs immediately before the delivery of HFS overcame the effects of the preconditioning LFS on LTP induction. These results suggest that, in CA1 neurons, after a preconditioning LFS, activation of group I mGluRs caused by the test stimulation results in IP3Rs activation that leads to a failure of LTP induction.
authors.affiliation: Department of Physiology, Yamagata University School of Medicine, Yamagata 990-9585, Japan Laboratory for Developmental Neurobiology, Riken Brain Science Institute, Wako, Saitama 351-0198, Japan sfujii@med.id.yamagata-u.ac.jp.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Fujii
authors.affiliation: Department of Physiology, Yamagata University School of Medicine, Yamagata 990-9585, Japan.
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Yamazaki
authors.affiliation: Department of Physiology, Yamagata University School of Medicine, Yamagata 990-9585, Japan Laboratory for Developmental Neurobiology, Riken Brain Science Institute, Wako, Saitama 351-0198, Japan.
authors.forename: Jun-Ichi
authors.initials: J
authors.lastname: Goto
authors.affiliation: Department of Physiology, Yamagata University School of Medicine, Yamagata 990-9585, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Fujiwara
authors.affiliation: Laboratory for Developmental Neurobiology, Riken Brain Science Institute, Wako, Saitama 351-0198, Japan.
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Mikoshiba
mesh_terms: D000818:Animals; D001565:Benzoates / Q000494:pharmacology; D053119:Benzophenanthridines / Q000494:pharmacology; D001703:Biophysics; D001896:Boron Compounds / Q000494:pharmacology; D056547:CA1 Region, Hippocampal / Q000166:cytology*; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology*; D005998:Glycine / Q000031:analogs & derivatives / Q000494:pharmacology; D006168:Guinea Pigs; D007166:Immunosuppressive Agents / Q000494:pharmacology; D066298:In Vitro Techniques; D053496:Inositol 1,4,5-Trisphosphate Receptors / Q000378:metabolism*; D017774:Long-Term Potentiation / Q000187:drug effects / Q000502:physiology*; D008297:Male; D008734:Methoxyhydroxyphenylglycol / Q000031:analogs & derivatives / Q000494:pharmacology; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D016559:Tacrolimus / Q000494:pharmacology
chemical_list: D001565:Benzoates; D053119:Benzophenanthridines; D001896:Boron Compounds; D004791:Enzyme Inhibitors; D018691:Excitatory Amino Acid Antagonists; D007166:Immunosuppressive Agents; D053496:Inositol 1,4,5-Trisphosphate Receptors; D008734:Methoxyhydroxyphenylglycol; C079693:4-carboxyphenylglycine; C016299:chelerythrine; C109986:2-aminoethoxydiphenyl borate; D005998:Glycine; C010117:3,4-dihydroxyphenylglycol; D016559:Tacrolimus