Design-based stereological methods for counting neurons.

Recently developed stereological methods for counting neurons have a number of advantages over previously available stereological methods. These methods are most aptly referred to as 'design-based' because, in contrast to their predecessors, the probes and the sampling schemes that define the newer methods are 'designed', that is, defined a priori, in such a manner that one need not take into consideration the size, shape, orientation, and distribution of the objects to be counted. The elimination of the need for information about the geometry of the objects to be counted results in more robust data regarding estimates of total neuron number and neuronal loss because potential sources of systematic errors in the calculations are eliminated. In this article I will describe the salient features of the newer, design-based, methods and why they represent improvements over previously available methods.