Format

Send to

Choose Destination
Eur Arch Otorhinolaryngol. 2016 Feb;273(2):325-32. doi: 10.1007/s00405-014-3479-3. Epub 2015 Jan 31.

Expression of immediate-early genes in the dorsal cochlear nucleus in salicylate-induced tinnitus.

Hu SS1,2, Mei L1,2, Chen JY1,2, Huang ZW3,4, Wu H1,2.

Author information

1
Department of Otolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, 1665 Kongjiang Road, Shanghai, 200092, China.
2
Ear Institute, Shanghai Jiao Tong University School of Medicine, 1665 Kongjiang Road, Shanghai, 200092, China.
3
Department of Otolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, 1665 Kongjiang Road, Shanghai, 200092, China. huangzw86@gmail.com.
4
Ear Institute, Shanghai Jiao Tong University School of Medicine, 1665 Kongjiang Road, Shanghai, 200092, China. huangzw86@gmail.com.

Abstract

Spontaneous neuronal activity in dorsal cochlear nucleus (DCN) may be involved in the physiological processes underlying salicylate-induced tinnitus. As a neuronal activity marker, immediate-early gene (IEG) expression, especially activity-dependent cytoskeletal protein (Arc/Arg3.1) and the early growth response gene-1 (Egr-1), appears to be highly correlated with sensory-evoked neuronal activity. However, their relationships with tinnitus induced by salicylate have rarely been reported in the DCN. In this study, we assessed the effect of acute and chronic salicylate treatment on the expression of N-methyl D-aspartate receptor subunit 2B (NR2B), Arg3.1, and Egr-1. We also observed ultrastructural alterations in the DCN synapses in an animal model of tinnitus. Levels of mRNA and protein expression of NR2B and Arg3.1 were increased in rats that were chronically administered salicylate (200 mg/kg, twice daily for 3, 7, or 14 days). These levels returned to baseline 14 days after cessation of treatment. However, no significant changes were observed in Egr-1 gene expression in any groups. Furthermore, rats subjected to long-term salicylate administration showed more presynaptic vesicles, thicker and longer postsynaptic densities, and increased synaptic interface curvature. Alterations of Arg3.1 and NR2B may be responsible for the changes in the synaptic ultrastructure. These changes confirm that salicylate can cause neural plasticity changes at the DCN level.

KEYWORDS:

Arg3.1; Dorsal cochlear nucleus; Egr-1; NR2B; Tinnitus

PMID:
25636249
DOI:
10.1007/s00405-014-3479-3
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Springer
Loading ...
Support Center