Effect of monaural plugging on the density of glutamate-receptor in the inferior collicular neurons of the gerbil

Aim: To study the effect of monaural plugging on the density of Glu-receptor in the inferior collicular (including ICd, ICx and ICc) neurons of the gerbil. Methods: Thirty gerbils were used. 4 weeks after plugging one side ear of gerbils at the different postnatal ages (21, 42 and 70 dpn), the autoradiographaic technique was used to observe and compare the silver density which represented the Glu receptor of every section in the inferior collicular neurons in the different groups of gerbils. Results: In the adult-plugging groups, the densities of the Glu-receptor in the bilateral IC neurons showed no difference. In the 3-week-plugging and 6-week-plugging groups, the density of Glu-receptor in the contralateral neurons was significantly lower than that in neurons of plugging side (ICd: t = 2.53, P = 0.0186; t = 1.77, P = 0. 0443; ICx: t = 1.90, P = 0.0359, t = 2.03, P = 0.0367; ICc: t = 2.95, P = 0.0175, t = 2.35, P = 0.0208, moreover, in ICc section of the 3-week-plugging group the density ratio of Glu-receptor of two sides was the smallest (0.61 ± 0.03). Conclusion: The monaural plugging within 6 weeks postnatally has significant effect on the density of Glu-receptors in the inferior collicular neurons. The auditory functional development of IC related to Glu receptor is extend to 6 weeks postnatal.