Cytoarchitecture Of Cells Research Articles

Cationic ferritin uptake by cultured anterior pituitary cells treated with the proteinase inhibitor, BOC-DPhe-Phe-Lys-H.

Cultured cells from the anterior pituitary glands of adult rats were treated with the tripeptide aldehyde proteinase inhibitor, BOC-DPhe-Phe-Lys-H. The addition of this tripeptide aldehyde decreased the in vitro release of prolactin to 25% of the control value, while the release of growth hormone in the same cultures decreased to 33% of the control value. Prolactin immunostaining was stronger in semithin sections of proteinase-inhibitor-treated cultures than in control sections. After 2 h treatment with the inhibitor, prolactin- and growth hormone-containing secretory granules were numerous, and the number of crinophagic vacuoles had increased. In the presence of the inhibitor, the overall cytoarchitecture of parenchymal cells was well preserved, and the pathway of the uptake of cationic ferritin appeared to be unaffected.

Somatosensory thalamus of a prosimian primate (Galago senegalensis). II. An HRP and Golgi study of the ventral posterolateral nucleus (VPL).

The topographic arrangement and cytoarchitecture of cells in the ventral posterolateral nucleus (VPL) of a prosimian primate (Galago senegalensis) were studied using horseradish peroxidase (HRP) and Golgi impregnation techniques. Following cortical implants of HRP, reactive neurons in VPL are organized into medially concave lamellae which extend through the dorsoventral and rostrocaudal dimensions of the nucleus. After implant in forelimb and hindlimb areas of motor-sensory cortex, labeled cells are confined to the medial (VPLm) and lateral (VPLl) portions of VPL, respectively. HRP-positive cells in the ventral part of each lamella are organized into clusters which correspond to the clusters of cells and "parcellated-bursts" of preterminal debris previously described in bushbaby VPL (Pearson and Haines, this volume). HRP-reactive cells in the ventral intermediate nucleus (Vim) are evenly distributed as contrasted to the tightly clustered groups of somata in the adjacent VPL. This evidence argues in favor of the presence of Vim in dorsal thalamus of this prosimian. Golgi impregnations reveal two main types of relay cells in Galago VPL. Type I cells have multiangular somata, straight distal dendrites, and primary dendritic branch points which are free of appendages. Tye II cells have rounded somata, sinuous distal dendrites, and clusters of appendages located at primary branch points. Intermediate cells (i.e., cells with morphological features in between types I and II) are also present in VPL. Comparison of tufted Golgi impregnated cells with neurons labeled with HRP shows definite similarities in somata size and shape, and in the orientation of proximal dendrites. This evidence corroborates the relay nature of the tufted neurons in VPL. Relay cells in Galago VPL have morphological features which are similar to those of relay cells in lateral and medial geniculate nuclei of cat and primate. Type III cells have small round somata, radiate dendrites with elaborate appendages, and axons which appear to be intrinsic to VPL. Consequently, these cells are considered to be interneurons in the VPL of Galago. Glial-like neurons (type IV cells) were also observed. These have beaded dendritic processes similar to those which presumably represent presynaptic boutons in other species. Consequently, these cells are also assumed to function intrinsically within VPL.

Efferent projections of the gracile nucleus in the cat

The efferent projections of different portions of the gracile nucleus in the cat were studied using both autoradiographic and degeneration tracing methods. The results suggest that there are two aspects to the functional organization of these projections. First, the somatotopic organization of the gracile n. (GR) is maintained, but inverted, by the topographic organization of its projections to VPL1. Fibers from the lateral portions of GR terminate medially in VPL1; fibers from the dorsal portions terminate ventrally. These fibers, especially those from the middle and caudal portions of GR, terminate in dense, precisely located groups of clusters. Dorsally located clusters in VPL1 (predominantly from middle-ventral portions of GR) are significantly smaller than ventrally located clusters (predominantly from middle-dorsal portions). The second aspect of this organization, involving the projections both to VPL1 and to other brain stem targets, is that some kind of functionally relevant sorting process appears to occur as fibers leave different portions of the gracile n. The afferent projections of the rostral (GRr) and middle-ventral portions (GRmv) of the gracile n. are different from those from the other portions of the nucleus. Projections to VPL1 from GRr are less dense, less likely to form clusters, less clearly topographically organized, and extend further rostrally and dorsally in VPL1 than those from the rest of GR. The clusters are small, like those from GRmv. Similarly, although all portions of GR project to several other brain stem regions, these projections appear to be derived preferentially from GRr and/or GRmv. These brain stem regions involve certain portions of the inferior olive, inferior and superior colliculi, red n., zona incerta, pretectum, thalamic posterior group and the H field of Forel. This dual organization of efferent connectivity is similar to that of the cuneate n.20, and is consistent with many of the differences in cytoarchitecture, afferent connectivity and response properties of cells within different portions of the dorsal column nuclei.

Cytoarchitecture of monoamine-containing cells in the frog's gustatory epithelium

With the availability of 5,6-dihydroxytryptamine, the overall morphology and the characteristics distribution of monoamine-containing cells in the frog's gustatory epithelium came to be clearly elucidated by fluorescence histochemistry.

Die Beeinflussung der Gametangienbildung bei den Characeen.

Giant internodal cells of characean green algae have been widely used for studying cellular physiology. This review emphasizes their significance for understanding cytoarchitecture and cytoplasmic reorganization. The cytoarchitecture of internodal cells undergoes pronounced, cytoskeleton-dependent changes during development and in response to environmental cues. Under bright light, internodes develop alternating bands of acid and alkaline pH at their surface that correlate with the differential size and abundance of cortical organelles and, in the genus Chara, with the size and distribution of convoluted plasma membrane domains known as charasomes. Wounding induces responses ranging from chloroplast detachment to deposition of wound walls. These properties and the possibility for mechanical manipulation make the internodal cell ideal for exploring plasma membrane domains, organelle interactions, vesicle trafficking, and local cell wall deposition. The significance of this model system will further increase with the application of molecular biological methods in combination with metabolomics and proteomics.