Kanamycin-induced changes in cochlear hair cells of the guinea pig
PG Lundquist, J Wersäll - Zeitschrift für Zellforschung und Mikroskopische …, 1966 - Springer
PG Lundquist, J Wersäll
Zeitschrift für Zellforschung und Mikroskopische Anatomie, 1966•SpringerElectron-microscopical studies on the organ of Corti in kanamycin-intoxicated guinea pigs
showed that progressive changes occurred in the cochlear hair cells. The changes
appeared first in the basal turn of the organ of Corti, and affected primarily the outer hair-
cells. During the later stages of intoxication, degeneration spread from the basal turn
upwards, in the direction of the apex of the cochlea and, finally, affected all the external hair-
cells. The early changes caused clumping of the chromatin in the nucleus, swelling of the …
showed that progressive changes occurred in the cochlear hair cells. The changes
appeared first in the basal turn of the organ of Corti, and affected primarily the outer hair-
cells. During the later stages of intoxication, degeneration spread from the basal turn
upwards, in the direction of the apex of the cochlea and, finally, affected all the external hair-
cells. The early changes caused clumping of the chromatin in the nucleus, swelling of the …
Summary
Electron-microscopical studies on the organ of Corti in kanamycin-intoxicated guinea pigs showed that progressive changes occurred in the cochlear hair cells. The changes appeared first in the basal turn of the organ of Corti, and affected primarily the outer hair-cells. During the later stages of intoxication, degeneration spread from the basal turn upwards, in the direction of the apex of the cochlea and, finally, affected all the external hair-cells.
The early changes caused clumping of the chromatin in the nucleus, swelling of the nuclear membrane, damage in the mitochondria, with vesiculation of the mitochondrial cristae, and the formation of lamellated structures. The lysosomes were converted into dense bodies exhibiting various degeneration patterns. The ribosomes disappeared at an early stage from the cytoplasm.
Even in cells where severe changes had occurred the hairs and cuticle seemed to be intact.
During the final stages the plasma membrane, as well as the hairs and cuticle, was destroyed, and only remnants of these structures remained.
Even after the disappearance of the sensory cells and the afferent nerve endings, some efferent nerve endings were still present in the organ of Corti.
The action of kanamycin seems to differ slightly from that of streptomycin, since the changes caused by kanamycin in the plasma membrane are a fairly late effect, whereas the earliest changes occur apparently in the RNA protein-synthesis system and in the mitochondria of the external hair-cells.
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