Summary
The cell bodies of pyramidal cells in layers II and V of rat auditory cortex were quantitatively examined in groups of rats 3, 6, 15, 23, 27 and 34–36 months of age. The mean diameters of cell bodies of both layer II and layer V neurons, as measured in 1 μm plastic sections, increased between 3 and 15 months of age, then decreased to a diameter that was less in the 36-month-old than in the 3-month-old rats. Morphometry of the nuclei of the cells was done by measuring nuclear area and nuclear envelope length directly on electron micrographs. In the layer II cells, neither parameter changed with advancing age. In the layer V cells, the mean nuclear area decreased significantly in the old animals and the mean envelope length increased. Point-counting techniques were applied to electron micrographs of cell bodies to determine the relative volume of selected organelles, inclusions and ground substance in the perikaryal cytoplasm. In this part of the study the chronological pattern of change in layer II and layer V pyramidal cells was similar. The relative volume of dense bodies increased linearly with advancing age, with a slightly more accelerated rate in layer II cells. The relative volume of ground substance remained essentially constant through 27 months, and then at 34–36 months decreased to 83% and 89% of the three-month level in layer V and layer II, respectively. The relative volume of the rough endoplasmic reticulum (RER) did not change significantly until after 15 months, at which time it began to occupy increasingly a larger fraction of the perikaryal cytoplasm. Finally, the relative volumes of mitochondria, multivesicular bodies and Golgi apparatus did not show clear trends of change during the 33-month period.
Similar content being viewed by others
References
Brizzee, K. R. (1973) Quantitative histological studies on aging changes in cerebral cortex of rhesus monkey and albino rat with notes on effects of prolonged low-dose ionizing irradiation in the rat.Progress in Brain Research 40, 141–60.
Brizzee, K. R., Cancilla, P. A., Sherwood, N. andTimiras, P. S. (1969) The amount and distribution of pigments in neurons and glia of the cerebral cortex.Journal of Gerontology 24, 127–35.
Enesco, H. (1967) Cytophotometric analysis of DNA content of rat nuclei in aging.Journal of Gerontology 22, 445–8.
Feldman, M. L. andPeters, A. (1972) Intranuclear rods and sheets in rat cochlear nucleus.Journal of Neurocytology 1, 109–27.
Field, E. J. andPeat, A. (1971) Intranuclear inclusions in neurons and glia: A study in the aging mouse.Gerontologia 17, 129–38.
Hasan, M. andGlees, P. (1973) Ultrastructural age changes in hippocampal neurons, synapses and neuroglia.Experimental Gerontology 8, 75–83.
Hilliard, J. E. (1968) Measurement of volume in volume. InQuantitative Microscopy (edited byDehoff, R. T. andRhines, F. N.) pp. 45–75. New York: McGraw-Hill.
Hinds, J. W. andMcNelly, N. A. (1977) Ageing of the rat olfactory bulb; growth and atrophy of constituent layers and changes in size and number of mitral cells.Journal of Comparative Neurology 171, 345–68.
Hinds, J. W. andMcNelly, N. A. (1978) Dispersion of cisternae of rough endoplasmic reticulum in aging CNS neurons: A strictly linear trend.American Journal of Anatomy 152, 433–9.
Johnson, J. E., Mehler, W. R. andMiquel, J. (1975) A fine structural study of degenerative changes in the dorsal column nuclei of aging mice. Lack of protection by vitamin E.Journal of Gerontology 30, 395–411.
Johnson, J. E. andMiquel, J. (1974) Fine structural changes in the lateral vestibular nucleus of aging rats.Mechanisms of Ageing and Development 3, 203–24.
Lin, K. H., Peng, Y. M., Peng, M-T. andTseng, T. M. (1976) Changes in the nuclear volume of rat hypothalamic neurons in old age.Neuroendocrinology 21, 247–54.
Machado-Salas, J. (1977)The nervous system of the old mouse. A morphological contribution to the study of aging. Ph.D. dissertation, Department of Anatomy, University of Calfornia, Los Angeles.
Sachs, H. G., Colgan, J. A. andLazarus, M. L. (1977) Ultrastructure of the aging myocardium: A morphometric approach.American Journal of Anatomy 150, 63–72.
Schmucker, D. L., Mooney, J. S. andJones, A. L. (1977) Age-related changes in the hepatic endoplasmic reticulum: A quantitative analysis.Science 197, 1005–7.
Seite, R., Leonetti, J., Luciani-Vuillet, J. andVio, M. (1977) Cyclic AMP and ultrastructural organization of the nerve cell nucleus: Stimulation of nuclear microtubules and microfilaments assembly in sympathetic neurons.Brain Research 124, 41–51.
Sekhon, S. S. andMaxwell, D. S. (1974) Ultrastructural changes in neurons of the spinal anterior horn of aging mice with particular reference to the accumulation of lipofuscin pigment.Journal of Neurocytology 3, 59–72.
Sokal, R. R. andRohlf, F. J. (1969)Biometry. San Francisco: W. H. Freeman and Company.
Vaughan, D. W. (1977) Age-related deterioration of pyramidal cell basal dendrites in rat auditory cortex.Journal of Comparative Neurology 171, 501–16.
Vaughan, D. W. andPeters, A. (1974) Neuroglial cells in the cerebral cortex of rats from young adulthood to old age: An electron microscope study.Journal of Neurocytology 3, 405–29.
Weibel, E. R. (1969) Stereological principles for morphometry in electron microscope cytology.International Review of Cytology 26, 235–302.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Vaughan, D.W., Vincent, J.M. Ultrastructure of neurons in the auditory cortex of ageing rats: a morphometric study. J Neurocytol 8, 215–228 (1979). https://doi.org/10.1007/BF01175562
Received:
Revised:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF01175562