Based on their morphology, the most abundant cells within nervous tissue of central system, astrocytes, can be divided into two types, protoplasmic astrocytes and fibrous astrocytes. A further analysis brain with preserved from human principal olivary nucleus, based morphological differences age, is successfully performed in this paper. Moreover, images 294 148 146 protoplasmic, nucleus were us...

The potential difference across the protoplasm of impaled cells of two American species of Halicystis is compared. The mean value for H. Osterhoutii is 68.4 mv.; that for H. ovalis is 79.7 mv., the sea water being positive to the sap in both. The higher potential of H. ovalis is apparently due to the higher concentration of KCl (0.3 M) in its vacuolar sap. When the KCl content of H. Osterhoutii...

1. Survival of cells without cell proliferation. 2. Cell multiplication without increase in protoplasmic matter, due to the presence of substances stimulating mitosis and the absence of the proper nutritive elements in the culture medium. 3. Proliferation of cells with new formation of protoplasmic matter through utilization of nutritive substances contained in t,he culture medium under conditi...

A mutation (modD) was selected in a gene involved in the control of protoplasmic incompatibility. Previous results (Labarere and Bernet 1979) showed that modD decreased the density of protoperithecia and caused a defect in ascospore germination. In addition, modD has a third defect: when modD stationary cells were isolated in order to obtain further development, renewal of growth rarely ensued....

We have recently described "fracture-label" techniques that permit direct cytochemical labeling of freeze-fractured cells. We report here the use of fracture-labeling to investigate the distribution and partition of wheat germ agglutinin (WGA) receptor sites over the protoplasmic and exoplasmic plasma membrane faces of freeze-fractured human thymus-derived (T) lymphocytes. All exoplasmic faces ...