SciELO - Scientific Electronic Library Online

vol.29 issue1Calcium Levels in the Maxillae of Human FoetusesEffect of Aspirin on the Developing Teeth of Neonates author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Services on Demand




Related links


International Journal of Morphology

On-line version ISSN 0717-9502


VASCONCELOS, Carlos Augusto Carvalho de et al. Transmission Electron Microscopy Studies of the Vestibulocochlear Nerve in Chronic Diabetic Rats. Int. J. Morphol. [online]. 2011, vol.29, n.1, pp.272-277. ISSN 0717-9502.

It is widely described in the literature that diabetic patients present hearing impairment. Despite the histological alterations of the internal ear structures in these patients as well as in experimental models of diabetes, to the best of our knowledge, an histological evaluation of the vestibulocochlear nerve have not been performed. In the present study, ultrastructural alterations are described and compared between a spinal nerves and a cranial nerve in rats with chronic induced diabetes. Male Wistar rats (n = 12), fed with standard diet from the animal care facility at 42 days of age were used. Induced diabetic animals (n=6) were fasted for 12 hours prior to being injected intraperitoneally with streptozotocin (STZ - 60mg/kg) in a single dose. Control animals (n=6) received (0.01 mol/l citrate buffer, pH 4.5) vehicle alone. Ten weeks after STZ injection the animals were perfused intracardially with Karnovsky solution. Right and left vestibulocochlear nerves were dissected and histologically processed for epoxy resin embedding. Samples were imaged with the transmission electron microscope. Large myelinated fibers with morphological signs of axonal atrophy in the vestibulocochlear nerves were readily observed. These results suggest that chronic STZ-induced diabetes in rats caused alterations in the myelinated fibers and Schwann cells, compatible to the classic diabetes signs and symptoms. Morphological alterations of the vestibulocochlear nerve in diabetes is described for the first time and contributes information for a better understanding of why there are changes in hearing observed in diabetic patients.

Keywords : Experimental diabetes; Vestibulocochlear nerve; Ultrastructure; Myelinated fibers; Axonal atrophy.

        · abstract in Spanish     · text in English     · English ( pdf )


Creative Commons License All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License