ABSTRACT
Objective To study the changes of N-methyl-D-aspartate receptors(NMDARs) expression at local sy-(napses) in auditory cortices after ototoxic deafened and following electrical intracochear stimulation(EIS).Methods We prepared highly purified synaptosomes from primary auditory cortex by two discontinuous gradient centrifugations, and compared the differences of NMDA receptors expression in ototoxic deafened group control group, normal control group and different experimental groups (EIS from 0.5h to 2h ) by Western blotting.Results We found that EIS for as little as half and one hour the adult and developmental rats of auditory deprivation can induce a significant increase in NMDAR subunit2A (NR2A) protein. But the changes of NMDAR subunit1(NR1) and NMDAR subunit2B(NR2B) are not significant.Conclusion There is a rapid activity-dependent expression of synaptic NR2A receptors in primary auditory cortex in vivo.