Variation of CREB and NMDAR1 Proteins Induced by Auditory Deprivation and Intracochlear Electrical Stimulation in Infant Rats / 听力学及言语疾病杂志

ABSTRACT

Objective To observe the expression of cAMP -response element binding protein (CREB) and N-methyl-D-aspartic acid receptor (NMDA ) after intracochlear electrical stimulation in the auditory cortex and inferior colliculus in infant rats with auditory deprivation .Methods Sixty six SD infant rats were randomly divided into 6 groups (11 rats each group):4 weeks ,and 6 weeks after injection of ototoxic drug ,the control group ,and 3 weeks and 5 weeks after injection of ototoxic drug with intra -cochlear electrical stimulation for one week .Gentami-cin sulphate (350 mg/kg body weight) and frusemide (200 mg/kg body weight) were injected subcutaneously in the skin folds on the lateral abdominal side and the dorsal neck area ,respectively .The expression of CREB and NMDAR1protein were detected by immunohistological staining .Results The results of immunohisto -chemistry revealed that protein expression of CREB and NMDAR1 in 4 week group of injection increased as compared to the control group ,while decreasing as compared to intracochlear electrical stimulation group ,significantly .However ,protein expression of CREB and NMDAR1 in 6 week group of injection decreased as compared to the control group and in-tracochlear electrical stimulation group ,significantly .Conclusion Auditory deprivation could result in the expres-sion of protein of CREB and NMDAR1 in auditory cortex and inferior colliculus increasing in an early stage and then de-creasing in infant rats .Intracochlear electrical stimulation could result in the expression of proteins of CREB and NMDAR 1 in auditory cortex and inferior colliculus increasing in infant rats .The dynamic variation of CREB and NMDAR1 expression in rat auditory cortex and inferior colliculus reflects synaptic plasticity in neurons of auditory pathway .