3-DIMENSIONAL CYTOSKELETAL STRUCTURES OF THE CHINCHILLA ORGAN OF CORTI - SCANNING ELECTRON-MICROSCOPY APPLICATION OF THE POLYETHYLENE-GLYCOL METHOD

We describe the application of a polyethylene glycol (PEG) embedding t echnique to examine the sensory and supporting structures of the inner ear. The chinchilla organ of Corti was exposed by cracking PEG embedd ed cochleas. A range of PEG molecular weights (2000-8000) were utilize d; PEG 2000, with a melting point of 57 degrees C was preferred. After removal of the PEG, the three-dimensional aspects of intracellular st ructures were observed using scanning electron microscopy. Filamentous elements in the hair cell cuticular plate and in the supporting cells were clearly observed, as was the meshwork of cross-linked actin fila ments in the cuticular portion of sensory hair cells. Microtubule and microfilament alignment patterns in pillar and Deiters cells were also clearly demonstrated. Characteristic structures in the outer hair cel l synaptic region, such as the post-synaptic cistern and synaptic body , were well preserved using the PEG method.