TY - JOUR
T1 - Target-cell-specific left-right asymmetry of NMDA receptor content in Schaffer collateral synapses in ε1/NR2A knock-out mice
AU - Wu, Yue
AU - Kawakami, Ryosuke
AU - Shinohara, Yoshiaki
AU - Fukaya, Masahiro
AU - Sakimura, Kenji
AU - Mishina, Masayoshi
AU - Watanabe, Masahiko
AU - Ito, Isao
AU - Shigemoto, Ryuichi
PY - 2005/10/5
Y1 - 2005/10/5
N2 - Input-dependent left-right asymmetry of NMDA receptor ε2 (NR2B) subunit allocation was discovered in hippocampal Schaffer collateral (Sch) and commissural fiber pyramidal cell synapses (Kawakami et al., 2003). To investigate whether this asymmetrical ε2 allocation is also related to the types of the postsynaptic cells, we compared postembedding immunogold labeling for ε2 in left and right Sch synapses on pyramidal cells and interneurons. To facilitate the detection of ε2 density difference, we used ε1 (NR2A) knock-out (KO) mice, which have a simplified NMDA receptor subunit composition. The labeling density for ε2 but not ζ1 (NR1) and subtype 2/3 glutamate receptor (GluR2/3) in Sch-CA1 pyramidal cell synapses was significantly different between the left and right hippocampus with opposite directions in strata oriens and radiatum; the left to right ratio of ε2 labeling density was 1:1.50 in stratum oriens and 1.44:1 in stratum radiatum. No significant difference, however, was detected in CA1 stratum radiatum between the left and right Sch-GluR4-positive (mostly parvalbumin-positive) and Sch-GluR4-negative interneuron synapses. Consistent with the anatomical asymmetry, the amplitude ratio of NMDA EPSCs to non-NMDA EPSCs in pyramidal cells was approximately two times larger in right than left stratum radiatum and vice versa in stratum oriens of ε1 KO mice. Moreover, the amplitude of long-term potentiation in the Sch-CA1 synapses of left stratum radiatum was significantly larger than that in the right corresponding synapses. These results indicate that the asymmetry of ε2 distribution is target cell specific, resulting in the left-right difference in NMDA receptor content and plasticity in Sch-CA1 pyramidal cell synapses in ε1 KO mice.
AB - Input-dependent left-right asymmetry of NMDA receptor ε2 (NR2B) subunit allocation was discovered in hippocampal Schaffer collateral (Sch) and commissural fiber pyramidal cell synapses (Kawakami et al., 2003). To investigate whether this asymmetrical ε2 allocation is also related to the types of the postsynaptic cells, we compared postembedding immunogold labeling for ε2 in left and right Sch synapses on pyramidal cells and interneurons. To facilitate the detection of ε2 density difference, we used ε1 (NR2A) knock-out (KO) mice, which have a simplified NMDA receptor subunit composition. The labeling density for ε2 but not ζ1 (NR1) and subtype 2/3 glutamate receptor (GluR2/3) in Sch-CA1 pyramidal cell synapses was significantly different between the left and right hippocampus with opposite directions in strata oriens and radiatum; the left to right ratio of ε2 labeling density was 1:1.50 in stratum oriens and 1.44:1 in stratum radiatum. No significant difference, however, was detected in CA1 stratum radiatum between the left and right Sch-GluR4-positive (mostly parvalbumin-positive) and Sch-GluR4-negative interneuron synapses. Consistent with the anatomical asymmetry, the amplitude ratio of NMDA EPSCs to non-NMDA EPSCs in pyramidal cells was approximately two times larger in right than left stratum radiatum and vice versa in stratum oriens of ε1 KO mice. Moreover, the amplitude of long-term potentiation in the Sch-CA1 synapses of left stratum radiatum was significantly larger than that in the right corresponding synapses. These results indicate that the asymmetry of ε2 distribution is target cell specific, resulting in the left-right difference in NMDA receptor content and plasticity in Sch-CA1 pyramidal cell synapses in ε1 KO mice.
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U2 - 10.1523/JNEUROSCI.2134-05.2005
DO - 10.1523/JNEUROSCI.2134-05.2005
M3 - Article
C2 - 16207881
AN - SCOPUS:27144492704
VL - 25
SP - 9213
EP - 9226
JO - Journal of Neuroscience
JF - Journal of Neuroscience
SN - 0270-6474
IS - 40
ER -