Learn More
Earliest origins of macrophage populations in the central nervous system, the liver, and the lungs were studied in rat embryos aged between 10.5-11 days and 14 days of gestation, based on light and electron microscopic identification of macrophages using peroxidase-coupled isolectin B4 of Griffonia simplicifolia (GSA I-B4), which recognizes(More)
A quantitative study of the rat olfactory bulb during aging was carried out by directly measuring or calculating the following parameters at 3, 12, 24, 27, and 30 months: The volume of the glomerular, external plexiform, and internal granular layers, a relative measure of the size of the olfactory nerve layer, the mean volume of mitral cell nuclei and(More)
Two regions closely linked synaptically (olfactory epithelium and olfactory bulb) have been compared in an age-graded series of rats. Previous findings of growth and atrophy of constituent elements in Sprague-Dawley Wisconsin (SD) rats have now been confirmed in Charles River (Crl) rats. In the olfactory bulbs of Charles River (Crl) rats, the volume of(More)
In order to try to determine whether differentiated olfactory receptors turn over (die and are replaced by newly differentiated cells) during adult life, mice were injected with a single dose of 3H-thymidine at either 2 or 4 months of age and allowed to survive for up to 12 months; they were caged in a laminar flow unit to prevent rhinitis. Counts of(More)
Quantitative measurements of the major organelles in the mitral cell perikaryon as well as numbers of mitral somato-dendritic synapses, have been made on electron micrographs from rats aged 3 to 30 months. The volume fraction of the cisternae of rough endoplasmic reticulum (RER) is constant throughout the period studied. Hence the amount of RER per cell(More)
Macrophage precursors and their progeny have been identified in early rat embryos with the use of a peroxidase-coupled marker, isolectin B4 of Griffonia simplicifolia (GSA I-B4). The macrophage lineage can be traced back to actively dividing GSA-positive angular cells present in the mesenchyme of late neurulas. These increase in number and establish(More)
The population dynamics of internal granule cells in the rat olfactory bulb during adult life were analyzed in histological sections and in autoradiograms with (1) counts of granule cells, (2) counts of labeled granule cells 1 month after injection of 3H-thymidine at various ages, and (3) counts of labeled granule cells at varying survival times (up to 18(More)
Autoradiographs were prepared from lungs of a newborn Syrian golden hamster exposed continuously to [3H]thymidine throughout the final 4.5 days of gestation. Silver grains were counted over nuclei of 1,145 nonendocrine airway epithelial cells adjacent to 28 mature neuroepithelial bodies (NEBs). Generally, accumulated label was greater in cells nearer a NEB(More)
Autoradiographs were prepared from lungs of a newborn Syrian golden hamster exposed continuously to 3H-thymidine for the final 4.5 days of a normal 16 day gestation. Silver grains were counted over nuclei of 1,298 small-granule endocrine cells in 165 neuroepithelial bodies (NEBs) in the right upper lobe and along the left axial bronchus, where nodal NEBs(More)
Clusters of small-granule endocrine cells, neuroepithelial bodies (NEBs), appear in the airway lining of pseudoglandular lungs, but their prenatal function has remained obscure. Transplacental labeling of S-phase cells in Syrian golden hamsters has allowed us to relate NEBs to patterns of replication in the surrounding endoderm. Two methods were used: 1)(More)