Opposing Role of NMDA Receptor GluN2B and GluN2D in Somatosensory Development and Maturation

• Yamasaki, Miwako

• Okada, Rieko

• Takasaki, Chihiro

• Toki, Shima

• Fukaya, Masahiro

• Natsume, Rie

• Sakimura, Kenji

• Mishina, Masayoshi

• Shirakawa, Tetsuo

• Watanabe, Masahiko

抄録

Development of correct topographical connections between peripheral receptors and central somatosensory stations requires activity-dependent synapse refinement, in which the NMDA type of glutamate receptors plays a key role. Here we compared functional roles of GluN2B (GluR epsilon 2 or NR2B) and GluN2D (GluR epsilon 4 or NR2D), two major regulatory subunits of neonatal NMDA receptors, in development of whisker-related patterning at trigeminal relay stations. Compared with control littermates, both the appearance of whisker-related patterning and the termination of the critical period, as assessed by unilateral infraorbital nerve transection, were delayed by nearly a day in the somatosensory cortex of GluN2B(+/-) mice but advanced by nearly a day in GluN2D(-/-) mice. Similar temporal shifts were found at subcortical relay stations in the thalamus and brainstem of GluN2B(+/-) and GluN2D(-/-) mice. In comparison, the magnitude of lesion-induced critical period plasticity in the somatosensory cortex, as assessed following row-C whisker removal, was normal in both mutants. Thus, GluN2B and GluN2D play counteractive roles in temporal development and maturation of somatosensory maps without affecting the magnitude of critical period plasticity. To understand the opposing action, we then examined neuronal and synaptic expressions of the two subunits along the trigeminal pathway. At each trigeminal station, GluN2B was predominant at asymmetrical synapses of non-GABAergic neurons, whereas GluN2D was selective to asymmetrical synapses of GABAergic neurons. Together, our findings suggest that GluN2B expressed at glutamatergic synapses on glutamatergic projection neurons facilitates refinement of ascending pathway synapses directly, whereas GluN2D expressed at glutamatergic synapses on GABAergic interneurons delays it indirectly.

収録刊行物

• Journal of Neuroscience

  Journal of Neuroscience 34 (35), 11534-11548, 2014-08-27

  Society for Neuroscience

キーワード

• barrel
• critical period
• GluN2B
• GluN2D
• NMDA receptor
• somatosensory

詳細情報

• CRID: 1050845763947094528
• NII論文ID: 120005553664
• HANDLE: 2115/58008
• ISSN: 02706474
• 本文言語コード: en
• 資料種別: journal article
• データソース種別:
  • IRDB
  • CiNii Articles