Expression of immediate-early genes in the inferior colliculus and auditory cortex in salicylate-induced tinnitus in rat.
Tinnitus could be associated with neuronal hyperactivity in the auditory center. As a neuronal activity marker, immediate-early gene (IEG) expression is considered part of a general neuronal response to natural stimuli. Some IEGs, especially the activity-dependent cytoskeletal protein (Arc) and the early growth response gene-1 (Egr-1), appear to be highly correlated with sensory-evoked neuronal activity. We hypothesize, therefore, an increase of Arc and Egr-1 will be observed in a tinnitus model. In our study, we used the gap prepulse inhibition of acoustic startle (GPIAS) paradigm to confirm that salicylate induces tinnitus-like behavior in rats. However, expression of the Arc gene and Egr-1 gene were decreased in the inferior colliculus (IC) and auditory cortex (AC), in contradiction of our hypothesis. Expression of N-methyl d-aspartate receptor subunit 2B (NR2B) was increased and all of these changes returned to normal 14 days after treatment with salicylate ceased. These data revealed long-time administration of salicylate induced tinnitus markedly but reversibly and caused neural plasticity changes in the IC and the AC. Decreased expression of Arc and Egr-1 might be involved with instability of synaptic plasticity in tinnitus.
. hushousen@126.com.
S S
SS
Hu
L
L
Mei
J Y
JY
Chen
Z W
ZW
Huang
H
H
Wu
D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000009:adverse effects* / Q000494:pharmacology; D001303:Auditory Cortex / Q000378:metabolism* / Q000473:pathology; D003598:Cytoskeletal Proteins / Q000096:biosynthesis; D051766:Early Growth Response Protein 1 / Q000096:biosynthesis; D005786:Gene Expression Regulation / Q000187:drug effects*; D007245:Inferior Colliculi / Q000378:metabolism* / Q000473:pathology; D008297:Male; D009419:Nerve Tissue Proteins / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D012980:Sodium Salicylate / Q000009:adverse effects* / Q000494:pharmacology; D014012:Tinnitus / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology
D000894:Anti-Inflammatory Agents, Non-Steroidal; D003598:Cytoskeletal Proteins; D051766:Early Growth Response Protein 1; C486110:Egr1 protein, rat; D009419:Nerve Tissue Proteins; C092069:activity regulated cytoskeletal-associated protein; D012980:Sodium Salicylate