In this method, a series of digitized images is obtained of the specimen as it rotated under the electron beam. Thus, the images in the series represent views from different orientations. The digitized images are then processed by computer to derive a three-dimensional numerical representation of the specimen. This representation may visualized using computer graphics methods. One class of branches, the dendrites receives information.
Information is transmitted along another type, the axon.
The dendrites of many neurons possess small spines which appear as the mushroom like protuberances in the highly magnified view of a portion of a dendrite shown above. The head of the spine are about .5 micron in diameter. This view was derived using electron microscope tomography. In order to examine a large region of dendrite tomographic datasets were collected from five adjacent and overlapping regions of the dendrite. These five datasets were then merged on the computer to obtain the image.