A system for the three-dimensional reconstruction of biological structures

A system of programs for building three-dimensional models of biological structures was developed. Outlines of features such as cells, tissue edges, and neuron pathways are traced into a computer from tissue sections mounted on a light microscope or projected onto a data tablet. The three-dimensional models are built from a series of the two-dimensional outlines. The cathode ray tube displays of the three-dimensional models can be smoothly rotated for study, and a static display with hidden lines removed can be produced. Volume and surface area calculations for the models can be done. It is possible to obtain further anatomical data by counting and mapping silver grains in autoradiographs of tissue sections. The density of grains reveals pathways and boundaries in the structure. Displays of silver grain maps and counts can be superimposed on displays of the model of the structure.