Unbiased stereological estimation of the total number of neurons in the subdivisions of the rat hippocampus using the optical fractionator
Tóm tắt
A stereological method for obtaining estimates of the total number of neurons in five major subdivisions of the rat hippocampus is described. The new method, the optical fractionator, combines two recent developments in stereology: a three‐dimensional probe for counting neuronal nuclei, the optical disector, and a systematic uniform sampling scheme, the fractionator. The optical disector results in unbiased estimates of neuron number, i.e., estimates that are free of assumptions about neuron size and shape, are unaffected by lost caps and over‐projection, and approach the true number of neurons in an unlimited manner as the number of samples is increased. The fractionator involves sampling a known fraction of a structural component. In the case of neuron number, a zero dimensional quantity, it provides estimates that are unaffected by shrinkage before, during, and after processing of the tissue. Because the fractionator involves systematic sampling, it also results in highly efficient estimates. Typically only 100–200 neurons must be counted in an animal to obtain a precision that is compatible with experimental studies. The methodology is compared with those used in earlier works involving estimates of neuron number in the rat hippocampus and a number of new stereological methods that have particular relevance to the quantitative study of the structure of the nervous system are briefly described in an appendix.
Từ khóa
Tài liệu tham khảo
Andersen B. B. L.Korbo andB.Pakkenberg(1991)Stereological quantification in the human cerebellum(submitted).
Bagger P. V., 1989, Classification of isolated ovarian follicles using the nucleator: Estimation of antral volume, Acta Stereol., 8, 123
Bagger P. V. L.Bang M. D.Christiansen H. J. G.Gundersen E.Kabell‐Kjaer andL.Mortensen(1991) Total number of particles in a bounded region estimated directly using the nucleator: Granulosa cell number in ovarian follicles.Am. J. Obstet. Gynecol.(submitted).
Blackstad T. W., 1956, Commissural connections of the hippocampal region in the rat, with special reference to their mode of termination, J. Comp. Neurol., 182, 851
y Cajal S. R., 1893, Estructura del Asta de Ammon
Caverley R. K. S., 1987, Determination of the numerical density of perforated synapses in rat neocortex, Call Tissue Res., 248, 399
Evans S. M., 1989, Estimation of spatial distribution using the nucleator, Acta Stereol., 8, 395
Floderus S., 1944, Untersuchungen über den Bau der menschlichen Hypophyse mit besonderer Berücksichtigung der quantitativen mikromorphologischen Verhältnisse, Acta Pathol. Microbiol. Scand., 53, 1
Gundersen H. J. G.(1981)Stereologi eller hvordan tal for rumlig form og indhold opnås ved iagttagelse af strukturer på snitplaner. Lægeforeningens forlag Copenhagen.
Gundersen H. J. G.(1991) Stereology: The fast lane between neuroanatomy and brain function‐or still only a tightrope?Acta Neurol. Scand.(in press).
Holmes A. H., 1927, Petrographic Methods and Calculations
Korbo K. B. B.Andersen andA.Møller(1991) Unbiased estimation of the total number of neurons and glial cells and the distribution of Purkinje cell volumes in the rat cerebellar cortex.J. Neurosci. Methods(submitted).
Lorente De No R., 1934, Studies on the structure of the cerebral cortex. II. Continuation of the study of the ammonic system, J. Psychol. Neurol. (Lpz.), 46, 113
Madeira M. D., 1988, Unbiased estimate of hippocampal granule cell numbers in hypothyroid and in sex‐age‐matched control rats, J. Hirnforsch., 29, 634
Marcussen N.(1991)The 3‐dimensional number of capillaries in normal atubular and hypertrophic glomeruli(submitted).
Matheron G.(1971)The Theory of Regionalized Variables and Its Application. Les Cahiers du Centre de Morphologie Mathematique de Fontainebleau No. 5. Ecole Nationale Superieure des Mines de Paris.
Nyengaard J. R., 1988, Stereological estimation of the number of capillaries, exemplified by the renal glomerulus, APMIS Suppl., 96, 92
Seress L., 1988, Interspecies comparison of the hippocampal formation shows increased emphasis on the regio superior in the Ammon's horn of the human brain, J. Hirnforsch., 29, 335
Williams M. A., 1981, Sections of determined thickness for use in stereological estimations of cells, Stereol. Jugosl., 3, 369