The Neuronal Population: Numbers, Sizes, and Shapes
- 112 Downloads
As the light-microscope studies in the previous chapter have shown, there is evidence for precise neuronal orientation and for a segmental organization of neuron groups in the lateral nucleus of rats, which reaches a higher complexity in the dentate nucleus of the monkey. Further analysis of this organization will be the concern of the next two sections. The first of these will deal with a numerical and quantitative description of the neurons. (1) How large are the perikarya of the neurons? (2) Can they be classified according to their size? (3) Are there small neurons that can be clearly designated as the interneurons which have so far eluded the physiologists’ electrodes? (4) Can a quantitative estimate of perikaryal shape be made to augment the description of oriented elliptical neurons given in the previous chapter? Where are these oriented elliptical neurons and what proportion are they of the total neuronal population? In order to answer these questions for the dentate nucleus in both species, certain measurements of the neuronal population were made. In the rat, lengths, widths, and areas of 150 identified lateral nucleus neurons were measured in Nissl and Golgi preparations. In the monkey, the study was enlarged considerably to an extensive survey with the aid of computers, of lengths, widths, areas, ellipticity ratios, exact orientation, and locations of 1 541 neurons in coronal and horizontal planes.
KeywordsRhesus Monkey Round Cell Dentate Nucleus Horizontal Section Outer Margin
Unable to display preview. Download preview PDF.