A basic program to correct for split cell error in particles classified by the logarithm of their profile areas

Automated differential cell counting on a sector of the normal human hippocampus: the influence of age

The neurons and the glia of the human hippocampus are notoriously vulnerable in various pathological conditions including those linked to ageing. There may even be differences between the young and the old in the absence of manifest disease. Using an image analyser, systematic measurements of cell numbers in the region of the Sommer (Hl) sector of the human hippocampus have been made on post-mortem tissue from thirty-seven female and forty-nine male subjects aged between 15 and 96 years. In fifteen male and fifteen female subjects both hemispheres were available for analysis so that measurements were made on a total of 116 hemispheres. For each specimen the fresh volume of the hemisphere was measured and corrections subsequently made for changes in size which occurred during fixation, processing, mounting and staining. After all the correction factors had been applied the number of nucleolated neurons was found to fall by about 3.6% per decade (P less than 0.0001). There was no significant age-related change in the number of glia. Marked individual variations were found.

Quantitative morphological studies of neuropathological changes. Part 1

Quantitation of morphological changes in the nervous system is valuable for demonstrating different regions and cell types involved in a pathological process. Quantitative anatomical studies are numerous, whereas quantitations of pathological conditions are relatively few. This seems to be due partly to technical difficulties arising when comparing normal with pathological brain tissue. Shrinkage of the whole brain or of substructures is important but difficult to determine, and earlier studies are often inaccurate due to lack of precise measurement of this parameter. This review deals with three different technical aspects: (1) measurements at the macroscopical level, (2) the light microscopical morphometry, and (3) the stereological principles which are used primarily in electron microscopical quantitation. The most used techniques and formulas are reviewed in order to give an impression of the possibilities and requirements in quantitative neuropathology. After each of the major areas, macroscopical measurements, determination of nuclear and cell size and nuclear number, vascular network, and stereology, a few practical comments are given as well as references for further information on the topic. The quickly developing electronic image analysis is dealt with in the section on capillary network measurements and in the last, concluding section.

Using the Quantimet 720 image analyzing computer to count nucleolated neurones in the human brain

An approach to the automatic counting of neurones in the human hippocampus is described which uses a modified Quantimet 720 image analyzing computer. Previous work with this and similar machines has attempted to use size alone to discriminate between the various types of cell which are present in any section of central nervous system tissue. Serious errors may then result since agglomerates of small cells and cell fragments can bae confused with single large cells. Instead, 2 electron devices have been designed and built which allow nucleolated neurones, defined as those objects having a grey phase and a black phase both within designated area limits, to be distinguished from all other cells. The mean values for absolute cell numbers and for cell density were within 5% of those obtained by traditional manual methods. The operation of both electronic devices is described and circuit diagrams given for one of them. The other is beyond the scope of this paper, but has been fully reported elsewhere.

A computer system for combined neuronal mapping and morphometry

A computer system has been developed which allows both mapping and planimetry of histological preparations. Data consist of cytoarchitectonic boundaries defined in low-power micrographs of thick sections, and nuclear and vascular profiles defined in high-power micrographs of semi-thin sections taken from the original thick tissue, and landmarks common to both. Data from these different preparations and magnifications are entered into the computer on a digitizing tablet and are stored as points in a real-world coordinate system, along with profile labels, landmarks for alignment purposes, and section depth. Subsequent programs determine parameters such as area and perimeter for each profile, as well as its geometric center and relationship to the cytoarchitectonic boundary. This mapping parameter allows morphometric analysis of profiles as a function of their position. Other programs allow display and manipulation of data in 3 dimensions, cell counts, and stereology. Data acquisition is done in the laboratory, using a micro-computer; analysis and display are done on a large time-sharing computer connected to the small machine by a telephone interface.