Aging changes of the olfactory bulb of albino rats

ABSTRACT

The olfactory bulb plays a central role in relaying olfactory information from the olfactory epithelium to the olfactory cortex. Olfactory loss is a common age-related complaint that may be caused by changes in the anatomy of the structures required which are required for olfaction [for example, change in the olfactory bulb]. The aim of the work is to study the structural changes which occur during aging in the olfactory bulb of albino rats. Twenty albino rats were used. The animals were subdivided into two age groups adult and aged [24 months]. The animals were anaesthetized, perfused with appropriate fixative solution, then the animals were killed and brains were extracted and specimens of olfactory bulbs were dissected. For each group, some specimens were fixed in Bouin's fluid and after routine histological technique were embedded in paraffin. Other specimens were sectioned and stained with Einarson's Gallocyanine solution to study the cellular histology and morphology of the olfactory bulb. Other specimens were fixed in Golgi-Cox solution and embedded in cellodin and dendritic organization of the neurons of the olfactory bulb was examined. Also other specimens were fixed in 5% buffered glutaldehyde and electron microscopic technique was made, semi thin and ultra thin sections were obtained and examined to show the ultra structure of the neurons of olfactory bulb. The results revealed that aging induced reduction in the thickness of the layers of olfactory bulb, decreased neuronal density of the mitral cells with decreased dendritic arborization of the neurons. Also elecrtomicroscopic feature of the aged olfactory bulb revealed evidence of nuclear damage, perinuclear vacuolation, dilated Golgi and cisternia of rough endoplasmic reticulum with destructed mitochondria