Mechanisms of Noise-Induced Tinnitus: Insights from Cellular Studies.

Summary

This review synthesizes cellular studies of noise-induced tinnitus. Equivalent cochlear damage occurs in animals with and without tinnitus; what distinguishes tinnitus animals is distinct, synchronized spontaneous firing in cochlear-nerve-recipient brainstem neurons (e.g., DCN fusiform cells) that drives central activity into phantom perception. Isolating tinnitus-specific single-cell changes separates tinnitus mechanisms from those of hearing loss alone.

Key findings

• Cochlear damage alone doesn't cause tinnitus; tinnitus animals show distinct synchronized brainstem firing.
• Tinnitus can occur even with a normal audiogram.
• Frames the DCN as the induction site where a phantom-sound neural code emerges.