[The acoustic trauma in animal experiment: I. Morphological reaction in the guinea pig cochlea after traumatisation by shots (a scanning microscopical study) (author's transl)].

Guinea pigs were exposed to shots of a pistol under standardized experimental conditions. The organs of Corti were examined by SEM after surviving times of 5 min, 1, 5 and 10 days. In correlation to the acoustic trauma we found mainly three different ways of morphological reaction of sensory cells. After 1--3 shots alterations and even losts of stereocilia were observed mainly in the 2nd (and 1st) coil from base. Only the rows III and II of outer hair cells (OHC) were concerned while changes in inner hair cells (IHC) were not observed. 5--10 shots regularly caused more severe alterations in the 1st, 2nd (and 3rd) coils of the organ of Corti. The three rows of outer hair cells degenerated within 2--5 days, while inner hair cells did not show any changes of the surface when the pillar cells remained intact. (20) 40 or even 100 shots most often caused a complete damage of all sensory--and supporting cells. The cell detritus was abolished within 5 days. At this time the damaged organ of Corti was replaced by a flat epithelium on the intact basilar membrane.