Stereological Methods for Estimation of Total Number of Particles in an Organ

In structure-function relationship studies, stereological methods are applied to quantify structural qualities under investigation. In certain organs, like the brain, it is important to count the number of neurons associated with a particular function or region. The count gives an estimate of the electronic units available for a specific task or are endowed with a quantum of electrical energy. Similar studies can be extended in organs like the kidney, glands and muscles. Therefore, stereological methods enhance our knowledge of optimization of structure to function in biological design. This paper expounds on the methods used in estimation of number of particles in three-dimensional space. It articulates a historical perspective of the development of particle counting techniques to date in stereology showing how the problem was solved and a sound, practical and unbiased method developed. Two approaches are applied in counting particle number. The model based and the design based approach. The model-based approach assumes that the components under investigation are regular geometrical structures whose parameters can be quantified using regular geometrical methods. This counting method is biased, inefficient and difficult to apply in biological tissues. The design based approach applies a three dimensional sampling probe, the dissector and makes no assumptions about shape or size of the components under investigation as in model approach. The Kenya Veterinarian Vol. 29 2005: pp. 33-36