a1 Pharmacology Laboratories, Department of Pharmacy, The University of Aston in Birmingham, Gosta Green, Birmingham B4 7ET.
a2 Department of Physiology, The Queen's University of Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast BT9 7BL.
Scanning electronmicroscopy and transmission electronmicroscopy were used to study the normal and gentamicin-damaged guinea-pig organ of Corti. Scanning electronmicroscopy was principally used to locate the lesion and quantify the cell loss but also permitted a detailed study to be made of the degenerative surface changes. However, since consistent surface changes are not seen until intracellular degeneration has progressed to a great extent, scanning electronmicroscopy is not a suitable technique for identifying early degenerative changes in the sensory cells of the organ of Corti. Consequently, before conclusions may be drawn about the absence of pathological changes in the neuro-epithelium it also should be examined using transmission electron-microscopy.