Oxytocin-immunoreactive nerve fibers in the pars intermedia of the pituitary in the rabbit and hare

1983 ◽  
Vol 228 (2) ◽  
Author(s):  
S. Schimchowitsch ◽  
M.E. Stoeckel ◽  
M.J. Klein ◽  
J.C. Garaud ◽  
G. Schmitt ◽  
...  
Keyword(s):  
Nerve Fibers ◽  
Pars Intermedia

Grass carp somatolactin: I. Evidence for PACAP induction of somatolactin-α and -β gene expression via activation of pituitary PAC-I receptors

2008 ◽  
Vol 295 (2) ◽  
pp. E463-E476 ◽  
Author(s):  
Quan Jiang ◽  
Wendy K. W. Ko ◽  
Ethan A. Lerner ◽  
K. M. Chan ◽  
Anderson O. L. Wong
Keyword(s):  
Gene Expression ◽  
Grass Carp ◽  
Primary Cultures ◽  
Single Copy ◽  
Nerve Fibers ◽  
Pars Intermedia ◽  
Pituitary Hormone ◽  
Pituitary Cells ◽  
Mrna Levels ◽  
Rapid Amplification

Somatolactin (SL), the latest member of the growth hormone/prolactin family, is a novel pituitary hormone with diverse functions. At present, SL can be identified only in fish but not in tetrapods and its regulation at the pituitary level has not been fully characterized. Using grass carp as a model, we examined the direct effects of pituitary adenylate cyclase-activating polypeptide (PACAP) on SL secretion and synthesis at the pituitary cell level. As a first step, the structural identity of grass carp SL, SLα and SLβ, was established by 5′/3′-rapid amplification of cDNA ends. These two SL isoforms are single-copy genes and are expressed in two separate populations of pituitary cells located in the pars intermedia. In the carp pituitary, PACAP nerve fibers were detected in the nerve tracts of the neurohypophysis and extended into the vicinity of pituitary cells forming the pars intermedia. In primary cultures of grass carp pituitary cells, PACAP was effective in stimulating SL release, cellular SL content, and total SL production. The increase in SL production also occurred with parallel rises in SLα and SLβ mRNA levels. With the use of a combination of molecular and pharmacological approaches, PACAP-induced SL release and SL gene expression were shown to be mediated by pituitary PAC-I receptors. These findings, as a whole, suggest that PACAP may serve as a hypophysiotropic factor in fish stimulating SL secretion and synthesis at the pituitary level. Apparently, PACAP-induced SL production is mediated by upregulation of SLα and SLβ gene expression through activation of PAC-I receptors.

scholarly journals Localization, expression and control of adrenocorticotropic hormone in the nucleus preopticus and pituitary gland of common carp (Cyprinus carpio L.)

2004 ◽  
Vol 182 (1) ◽  
pp. 23-31 ◽  
Author(s):  
◽  
MO Huising ◽  
J Meek ◽  
AJ Taverne-Thiele ◽  
SE Wendelaar Bonga ◽  
...  
Keyword(s):  
Pituitary Gland ◽  
Common Carp ◽  
Cyprinus Carpio ◽  
Adrenocorticotropic Hormone ◽  
Quantitative Polymerase Chain Reaction ◽  
Nerve Fibers ◽  
Pars Intermedia ◽  
Beta Endorphin ◽  
Common Carp Cyprinus Carpio ◽  
Carp Cyprinus Carpio

Adrenocorticotropic hormone (ACTH) takes a central role in the hypothalamo-pituitary-interrenal axis (HPI axis), which is activated during stress. ACTH is produced by the corticotrope cells of the pituitary pars distalis (PD) and is under control of factors from the nucleus preopticus (NPO). The distribution of ACTH in the hypothalamo-pituitary system in common carp (Cyprinus carpio L.) was assessed by immunohistochemistry. ACTH and beta-endorphin immunoreactivity was observed in the ACTH cells in the PD and in the NPO. Nerve fibers, originating from the NPO and projecting to the pituitary gland, contain beta-endorphin, but not ACTH, and these fibers either control the pituitary pars intermedia (PI) through beta-endorphin or release it to the blood. The release of pituitary ACTH (studied in a superfusion setup) must in vivo be under predominant inhibitory control of dopamine. Release of ACTH is stimulated by corticotropin-releasing hormone, but only when ACTH cells experience dopaminergic inhibition. The expression of the precursor pro-opiomelanocortin in (POMC) NPO, PD and PI was studied in an acute restraint stress paradigm by real-time quantitative polymerase chain reaction (RQ-PCR). POMC gene expression is upregulated in these three key tissues of the hypothalamo-pituitary complex, revealing a hitherto unforeseen complex role for POMC-derived peptides in the regulation of responses to stress.

Some Biological Applications of High Voltage Electron Microscopy

1974 ◽  
Vol 32 ◽  
pp. 298-299
Author(s):  
Hans Ris
Keyword(s):  
High Voltage ◽  
Chromosome Structure ◽  
Nerve Fibers ◽  
Good Resolution ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron ◽  
University Of Wisconsin ◽  
High Voltage Electron ◽  
One Year ◽  
The University

The High Voltage Electron Microscope Laboratory at the University of Wisconsin has been in operation a little over one year. I would like to give a progress report about our experience with this new technique. The achievement of good resolution with thick specimens has been mainly exploited so far. A cold stage which will allow us to look at frozen specimens and a hydration stage are now being installed in our microscope. This will soon make it possible to study undehydrated specimens, a particularly exciting application of the high voltage microscope.Some of the problems studied at the Madison facility are: Structure of kinetoplast and flagella in trypanosomes (J. Paulin, U. of Georgia); growth cones of nerve fibers (R. Hannah, U. of Georgia Medical School); spiny dendrites in cerebellum of mouse (Scott and Guillery, Anatomy, U. of Wis.); spindle of baker's yeast (Joan Peterson, Madison) spindle of Haemanthus (A. Bajer, U. of Oregon, Eugene) chromosome structure (Hans Ris, U. of Wisconsin, Madison). Dr. Paulin and Dr. Hanna are reporting their work separately at this meeting and I shall therefore not discuss it here.

Fine Structure of Planarian Neuroglial Cell

1976 ◽  
Vol 34 ◽  
pp. 188-189 ◽  
Author(s):  
Michio Morita ◽  
Jay Boyd Best
Keyword(s):  
Endoplasmic Reticulum ◽  
Ventral Nerve Cord ◽  
Osmium Tetroxide ◽  
Golgi Body ◽  
Nerve Fibers ◽  
Neuroglial Cell ◽  
Glutaraldehyde Solution ◽  
Deep Indentation ◽  
Cytoplasmic Processes ◽  
Longitudinal Nerve

The species of the planarian Dugesia dorotocephala was used as the experimental animal to study a neuroglial cell in the ventral nerve cord. Animals were fixed with 3% buffered glutaraldehyde solution and postfixed with 1% buffered osmium tetroxide.The neuroglial cell is multipolar, expanding into three or four cytoplasmic processes with many daughter branches. Some neuroglial processes are found to extend perpendicular to the longitudinal nerve fibers, whereas others are seen to be parallel to them. The nucleus of the neuroglial cell is irregular in shape and frequently has a deep indentation. Convex portions of the nucleus seem to be related to the areas from which cytoplasmic processes are extended. Granular endoplasmic reticulum (Fig. 4), Golgi body (Fig. 2), mitochondria (Figs. 1 and 2), microtubules (Fig. 4), and many glycogen granules are observable in the electron dense neuroglial cytoplasm. Neuroglial cells are also observed to contain various sizes of phagosomes and lipids (Fig. 2).

Ultrastructural investigation of an adenoma of the pituitary post mortem

1987 ◽  
Vol 45 ◽  
pp. 622-623
Author(s):  
Shirley Siew ◽  
W. C. deMendonca
Keyword(s):  
Deleterious Effect ◽  
Anterior Lobe ◽  
Definitive Diagnosis ◽  
Pars Intermedia ◽  
Post Mortem ◽  
Close Apposition ◽  
Autopsy Material ◽  
Progressive Loss ◽  
Transmission Electron ◽  
Means Of Transmission

The deleterious effect of post mortem degeneration results in a progressive loss of ultrastructural detail. This had led to reluctance (if not refusal) to examine autopsy material by means of transmission electron microscopy. Nevertheless, Johannesen has drawn attention to the fact that a sufficient amount of significant features may be preserved in order to enable the establishment of a definitive diagnosis, even on “graveyard” tissue.Routine histopathology of the autopsy organs of a woman of 78 showed the presence of a well circumscribed adenoma in the anterior lobe of the pituitary. The lesion came into close apposition to the pars intermedia. Its architecture was more compact and less vascular than that of the anterior lobe. However, there was some grouping of the cells in relation to blood vessels. The cells tended to be smaller, with a higher nucleocytoplasmic ratio. The cytoplasm showed a paucity of granules. In some of the cells, it was eosinophilic.

Interpreting HVEM of muscle-cell impulse networks

1992 ◽  
Vol 50 (1) ◽  
pp. 126-127
Author(s):  
Paul DeCosta ◽  
Kyugon Cho ◽  
Stephen Shemlon ◽  
Heesung Jun ◽  
Stanley M. Dunn
Keyword(s):  
Structural Analysis ◽  
Muscle Cell ◽  
Electron Micrographs ◽  
Relative Size ◽  
Automatic Classification ◽  
Nerve Fibers ◽  
Analysis Algorithm ◽  
Structural Networks

Introduction: The analysis and interpretation of electron micrographs of cells and tissues, often requires the accurate extraction of structural networks, which either provide immediate 2D or 3D information, or from which the desired information can be inferred. The images of these structures contain lines and/or curves whose orientation, lengths, and intersections characterize the overall network.Some examples exist of studies that have been done in the analysis of networks of natural structures. In, Sebok and Roemer determine the complexity of nerve structures in an EM formed slide. Here the number of nodes that exist in the image describes how dense nerve fibers are in a particular region of the skin. Hildith proposes a network structural analysis algorithm for the automatic classification of chromosome spreads (type, relative size and orientation).

The innervation of toad lymph hearts: An ultrastructural study

1992 ◽  
Vol 50 (1) ◽  
pp. 898-899
Author(s):  
A.M. Pucci ◽  
C. Fruschelli ◽  
A. Rebuffat ◽  
M. Guarna ◽  
C. Alessandrini ◽  
...  
Keyword(s):  
Ultrastructural Study ◽  
Neuromuscular Junctions ◽  
Nerve Fibers ◽  
Lack Of Information ◽  
Lymph Heart ◽  
Muscular Pump ◽  
Structure And Ultrastructure ◽  
Heart Wall

Amphibians have paired muscular pump organs, called “lymph heart”, which rhythmically pump back the lymph from the large subcutaneous lymph sacs into the veins. The structure and ultrastructure of these organs is well known but to date there is a lack of information about the innervation of lymph hearts. Therefore has been carried out an ultrastructural study in order to study the distribution of the nerve fibers, and the morphology of the neuromuscular junctions in the lymph heart wall.

Innervation of endoneurial microvessels in human sural nerve

1992 ◽  
Vol 50 (1) ◽  
pp. 920-921
Author(s):  
John L. Beggs ◽  
Peter C. Johnson ◽  
Astrid G. Olafsen ◽  
C. Jane Watkins
Keyword(s):  
Blood Flow ◽  
Blood Vessels ◽  
Blood Supply ◽  
Peripheral Nerves ◽  
Sural Nerve ◽  
Nerve Fibers ◽  
Arterial Supply ◽  
Autonomic Nerve ◽  
Vasa Nervorum ◽  
Endoneurial Blood Flow

The blood supply (vasa nervorum) to peripheral nerves is composed of an interconnected dual circulation. The endoneurium of nerve fascicles is maintained by the intrinsic circulation which is composed of microvessels primarily of capillary caliber. Transperineurial arterioles link the intrinsic circulation with the extrinsic arterial supply located in the epineurium. Blood flow in the vasa nervorum is neurogenically influenced (1,2). Although a recent hypothesis proposes that endoneurial blood flow is controlled by the action of autonomic nerve fibers associated with epineurial arterioles (2), our recent studies (3) show that in addition to epineurial arterioles other segments of the vasa nervorum are also innervated. In this study, we examine blood vessels of the endoneurium for possible innervation.

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