Yan-Hai Li and Jue Wang Pages 70 - 75 ( 6 )
N-methyl-D-aspartate receptors (NMDA-Rs) activation has been implicated in various forms of synaptic plasticity depending on the receptor subtypes involved. However, the contribution of NR2A and NR2B subunits in glycine-induced long-term potentiation (LTP) of miniature excitatory postsynaptic currents (mEPSCs) in layer II/III pyramidal neurons of the rat visual cortex remains unclear. The present study used whole-cell patch-clamp recordings in vitro to investigate the role of NR2A-containing and NR2B-containing NMDA-Rs in glycine-induced LTP in visual cortical slices from 13-15 day old rats. We found that glycine-induced LTP of mEPSCs was readily induced in layer II/III pyramidal neurons of the rat visual cortex with glycine. D-APV, a selective NMDA-R antagonist, blocked the glycineinduced LTP. Moreover, the selective NR2B-containing NMDA-R antagonists (Ro 25-6981) displayed no influence on the glycine-induced LTP. However, Zn2+, a voltage-independent NR2A-containing NMDA-R antagonist, prevented glycine-induced LTP. These results suggest that the glycine-induced LTP in layer II/III pyramidal neurons of the rat visual cortex is NMDA-R-dependent and requires NR2A-containing NMDA-Rs, not NR2B-containing NMDA-Rs.
Glycine, LTP, NMDA receptors, NR2A, NR2B, Rat, Visual cortex
The Key Laboratory of Biomedical Information Engineering of Ministry of Education, and Research Center of Rehabilitation Science and Technology, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an, Shaanxi 710049, P. R. China.