Effect of streptomycin on the otoconial layer of the guinea pig.

The effects of streptomycin on the otoconial layer of the adult guinea pig were investigated using scanning electron microscopy. Administration of streptomycin induced a reduction of otoconia with formation of giant otoconia. These phenomena reached their maximum 4 weeks after the cessation of streptomycin intoxication in the utricle and between 2 and 6 weeks after in the saccule. Otoconia began to recover in the utricle 4 weeks and in the saccule 6 weeks after the cessation of streptomycin intoxication with an increasing number of small otoconia. Eight or 10 weeks after the cessation of streptomycin intoxication, the otoconial layer has completely recovered in both the utricle and saccule.