title: [Developmental changes in synaptic and extrasynaptic N-methyl-D-aspartate receptors in cultured rat hippocampal neurons].
abstract: OBJECTIVE
  To investigate changes in synaptic and extrasynaptic N-methyl-D-aspartate receptors (NMDAR) during the development of cultured rat hippocampal neurons.
  
  
  METHODS
  Synaptic and extrasynaptic NMDAR channel currents were recorded from 1-day-old rat hippocampal neurons cultured for 1 and 2 weeks with patch-clamp technique in whole-cell configuration and outside-out configuration, respectively.
  
  
  RESULTS
  The amplitude of NMDAR-mediated miniature excited postsynaptic current (Meps(CNMDA)) decreased in neurons cultured for 2 weeks as compared with that recorded in neurons cultured for 1 week, and the 2-week neurons showed also much lowered sensitivity to selective NR2B blocker ifenprodil. The amplitude and open probability of extrasynaptic NMDAR in the 2-week neurons were significantly higher than those in the 1-week neurons, but the neurons differred little in conduction and reverse potential. Ifenprodil decreased the high conductance and open probability in both neurons, but the effect was more potent in the 2-week ones.
  
  
  CONCLUSIONS
  There can be developmental changes in synaptic and extrasynaptic NMDAR channel currents in cultured rat hippocampal neurons, indicating that different NMDAR subtypes are expressed in the synaptic and extrasynaptic regions during the development of the hippocampal neurons. In 1-week neurons, NR2B are predominant both in synaptic and extrasynaptic regions, and at 2 weeks, synaptic NR2B are replaced by NR2A but NR2B still remains the predominant subtypes outside the synapses.
authors.affiliation: Department of Physiology, School of Basic Medical Science, Southern Medical University, Guangzhou 510515, China. tianyh@fimmu.com
authors.forename: Ying-hong
authors.initials: YH
authors.lastname: Tian
authors.forename: De-hui
authors.initials: DH
authors.lastname: Hu
authors.forename: Shu-ji
authors.initials: SJ
authors.lastname: Li
authors.forename: Tian-ming
authors.initials: TM
authors.lastname: Gao
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002478:Cells, Cultured; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology; D006624:Hippocampus / Q000166:cytology; D009474:Neurons / Q000166:cytology / Q000502:physiology*; D018408:Patch-Clamp Techniques; D010880:Piperidines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D016194:Receptors, N-Methyl-D-Aspartate / Q000502:physiology*; D013569:Synapses / Q000502:physiology*; D009435:Synaptic Transmission / Q000502:physiology*; D013997:Time Factors
chemical_list: D018691:Excitatory Amino Acid Antagonists; C120997:NR2A NMDA receptor; C121001:NR2B NMDA receptor; D010880:Piperidines; D016194:Receptors, N-Methyl-D-Aspartate; C010739:ifenprodil