Effect of intermittent sound stimulation on cochlear microphonics and the possible preventive effect of coenzyme Q10

Observations have been made on the effect of intermittent intense sound stimuli, using the CM as an index. Experiments were conducted regarding the effectiveness of the drug CoQ10 in ameliorating the acoustic injury due to this traumatization. The CM was measured by the differential electrode method from the basal turn of the cochlea. The individual differences between animals were monitored using intensity functions. Pure tones at a frequency of 4 kHz were used both for the traumatizing signal and the CM generating signal. Acoustic traumatizing signals lasted 1 min with a 5 min silent interval, and were repeated 10 times. Both the chronic depression and the transient depression of CM were measured after each traumatization. In control animals, the chronic depression progressed in an exponential manner and the transient depression was constant after each stimulation. In CoQ10 treated animals, the chronic depression was milder than that in the control animals. The transient depression was equivalent in the two groups. The effectiveness of CoQ10 on the acoustic injury was discussed on the basis of the results obtained with the present experiment.