The Expression of GAP-43 in Cochlear Nucleus and Inferior Colliculus after Unilateral Cochlear Damage in Rats / 听力学及言语疾病杂志

ABSTRACT

Objective To study the changes of the expression of growth associated protein -43(GAP 43) in cochlear nucleus and the inferior colliculus (IC) in rats after unilateral cochlear damage at different time points after surgery ,and explore the remodeling and repair process of synapse in brainstem auditory center of rats after auditory deprivation .Methods Thirty rats were randomly divided into six groupsthe 3 ,7 ,15 ,30 ,60 days group (with u-nilateral cochlea damage) and the control group (without cochlea damage) with 5 rats in each group .The immuno-histochemical SP method was used to detect the expression of GAP -43 in cochlear nucleus and inferior colliculus at different time points after cochlea damaged in the control group .Results After the unilateral cochlear ear was dam-aged at 3 ,7 ,15 days ,GAP -43 in operation side cochlear nucleus were expressed and the expression level signifi-cantly increased compared with normal control group .After 30 days postoperatively ,GAP - 43 expression level decreased ,but it was still higher than normal control group .After 60 days postoperatively ,GAP - 43 expression level was slightly higher than that of normal control group .After 3 days postoperatively ,GAP - 43 expression level was higher than normal control group .After 7 ,15 days postoperatively ,expression levels were increased .After 30 , 60 days postoperatively ,the expressions gradually decreased ,but still higher than the normal control group .Conclusion After unilateral cochlea damaged ,GAP - 43 was expressed an obvious dynamic change process in cochlear nucleus and infe-rior colliculus .It may reflect the axonal regeneration and synaptic plasticity after hearing loss in brainstem auditory neurons .