RESUMO
Objective To investigate the cellular localization and developmental patterns of NMDA receptor subunits(NMDAR1 and NMDAR2A/B) in the ventral horn of rat spinal cord during postnatal stages. Method Immunohistochemical staining method was used in the present study. Results NMDAR1-or NMDAR2A/B-immunorectivity is abundantly observed in the lamina Ⅷ and Ⅸ of ventral horn.The immunopositive product is localized mainly in the neuronal somata,dendrites and axon terminals.Dynamic changes of NMDA receptor expression occur in early postnatal stages.NMDA receptor subunits express weakly at postnatal 7 days (P7),goes up at P14,reaches maximum level at P21,then remains this level until adult. Conclusion Neuronal functional NMDA receptors are composed of NMDAR1 and NMDAR2A in heteromeric configuration in the ventral horn of spinal cord;NMDA receptors may be involved in motor neuron maturation and plasticity during postnatal development.;