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Regulation of kinetic and pharmacological properties of synaptic NMDA receptors depends on presynaptic exocytosis in rat hippocampal neurones
Author(s) -
Lindlbauer Raimund,
Mohrmann Ralf,
Hatt Hanns,
Gottmann Kurt
Publication year - 1998
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1111/j.1469-7793.1998.00495.x
Subject(s) - ifenprodil , nmda receptor , neuroscience , hippocampal formation , glutamate receptor , neurotransmission , biology , excitatory postsynaptic potential , exocytosis , receptor , chemistry , microbiology and biotechnology , endocrinology , inhibitory postsynaptic potential , biochemistry , secretion
1 Using whole‐cell patch‐clamp recordings of NMDA EPSCs from co‐cultured rat hippocampal (CA region) neurones, developmental changes in the kinetic and pharmacological properties of synaptic NMDA receptors were investigated. During in vitro differentiation a fast decaying component increasingly contributed to NMDA EPSCs. 2 Extracellular Mg 2+ (1 mM) strongly blocked NMDA EPSCs at all stages in culture. Using the NR2B subunit‐specific NMDA receptor antagonist ifenprodil (3 μM), we observed a developmental decrease in ifenprodil sensitivity of NMDA EPSCs. This suggests developmental changes in the expression of NMDA receptor subtypes. 3 To transiently block presynaptic exocytosis, we incubated presynaptic explants with tetanus toxin (TeTx) prior to cultivation. In TeTx‐pretreated cultures the occurrence of fast decaying components of NMDA EPSCs and the developmental decrease in ifenprodil sensitivity was inhibited. Our results indicate a regulatory role of presynaptic exocytosis in the expression of NMDA receptor subtypes.