| Abstract: | A simple morphometnc method for accurate estimation of totalnumber of glomeruli in the olfactory bulb (OB), based on determinationof areas of individual glomeruli in representative serial histologicsections from the entire OB, is described. The procedure isbest utilized with the help of a computerized program for morphometry,although manual morphometric procedures may also be used. Thetotal volume of all the glomeruli in the OB is determined fromthe sum of the areas of the individual glomeruli per representativesection. This total volume is then divided by the volume ofa single glomerulus to obtain the total number of glomeruliin the OB. The method also describes procedures for determiningmeasured mean, corrected mean and maximal diameters and volumesof glomeruli and their distribution in the OB. It also describestwo different estimates for the total number of glomeruli, basedon whether the mean or maximal glomerular size are utilized.The estimation of total glomerular number by this method doesnot require the use of correction coefficients such as the Abercrombie'sand is independent of tissue shrinkage. Application of the methodis illustrated by determining the mean total number of glomeruliin the OB of a 25-day-old rat, which was found to be about 2400.The method can also be used for enumeration of total numberof glomeruli in a part of OB or for other relatively large spheroidmicroanatomical bodies like the taste buds within tongue papillae,follicles in the ovary, etc. The general validity of the methodis confirmed by using it to estimate a known total number ofspheroid objects placed in a block of agar. |
