Tinnitus is a ringing, swishing, or other type of noise that originated in the ear or brain.We hypothesize that damage of the cochlear hair cells causes hypersensitivity of the cells after a period of reorganization in the auditory pathway.A malfunctioning of the thalamic reticular nucleus (TRN) would decrease its inhibition to the auditory transmission and eventually causes tinnitus.In the present study, we would investigate the neuronal property change in the medial geniculate body (MGB) and inferior colliculus (IC) of the rats after cochlear ablation and TRN lesion at different timing.Kainic acid was injected into the TRN to lesion the nucleus.The contralateral cochlea to the recording hemisphere was ablated under an operating microscope.Spontaneous responses of the MGB and IC were recorded with the implanted extracellular electrodes while the rat was in different physiological conditions.We found that neurons in the auditory thalamus should more changes than those in the IC.The results would lead us to a further investigation on the potential mechanism focusing on the changes in the MGB.