Abstract
In our last study, we reported that the values of the EP deceased immediately after Barotrauma in guinea pigs without Preyer reflex, and they were injured of their auditory hair. So, in this time we investigated some guinea pigs whose Preyer reflex were still present after pressure loading. These had almost same EP values as normal guinea pigs. As to the generation of the EP in stria vascularis, these were almost under normal function. In addition, we observed the organ of corti, especially outer and inner haircells in any guinea pigs by using light microsope for every 4 days. And then, we found a structural disorder in outer hair cells at the time when the EP values decreased mostly. So we concluded that the primary damage of outer hair cells was concerned with EP decreasement.
