scholarly journals Ultrastructural and biochemical evidence for a steroid-containing secretory organelle in the perfused cat adrenal gland.

1977 ◽  
Vol 72 (1) ◽  
pp. 209-215 ◽  
Author(s):  
R T Gemmell ◽  
S G Laychock ◽  
R P Rubin
Keyword(s):  
Adrenal Gland ◽  
Cortical Cell ◽  
Underlying Mechanism ◽  
Acth Stimulation ◽  
Cortical Cells ◽  
Fourfold Increase ◽  
Dense Granules ◽  
Golgi Region ◽  
Close Proximity

A correlative study of the ultrastructural and biochemical effects of ACTH on fasciculata cells was carried out on the isolated cat adrenal gland perfused in situ with Locke's solution. The outstanding morphologic feature of cortical cells exposed to microunit ACTH concentrations for 40 min was the abundance of electron-dense granules (0.2-0.4 mum). These organelles were observed in small groups in close proximity to the Golgi region and to the cell membrane. Morphometric and biochemical analysis of control and ACTH-treated glands demonstrated that ACTH stimulation was associated with a fourfold increase in the number of these granules and a comparable increase in the corticosteroid content of the gland. By contrast, ACTH failed to augment cortical lysosomal enzyme activity. These findings, which link steroid release to the appearance of intracellular granules, extend further the parallels between the mechanism of release of newly synthesized steroid and the release of preformed hormones stored in secretory organelles. These results also lend support to the concept that a process related to exocytosis may be the underlying mechanism for extruding steroid from the cortical cell.

Adrenocorticotrophic hormone (ACTH) stimulation of sheep fetal adrenal cortex can occur without increased expression of ACTH receptor (ACTH-R) mRNA

2002 ◽  
Vol 14 (1) ◽  
pp. 1 ◽  
Author(s):  
A. M. Carter ◽  
Y. M. Petersen ◽  
M. Towstoless ◽  
D. Andreasen ◽  
B. L. Jensen
Keyword(s):  
Adrenal Gland ◽  
Mrna Expression ◽  
Ribonuclease Protection Assay ◽  
Acth Stimulation ◽  
Cortical Cells ◽  
Fetal Plasma ◽  
Chain Cleavage ◽  
Ribonuclease Protection ◽  
Sheep Fetus

In the present study, it was hypothesized that the adrenocorticotrophin hormone receptor (ACTH-R) would be up-regulated in the adrenal gland of the sheep fetus following infusion of physiological amounts of ACTH, as shown for adrenal cortical cells in culture. In chronically catheterized sheep, an intravenous infusion of ACTH1–24 was given to 6 fetuses for 24 h at a rate of 0.5 g h–1, starting on Day 126 or 127 of gestation (term ~147 days). Four control fetuses received an infusion of vehicle (saline). Total RNA was extracted from the fetal adrenal glands by the guanidinium thiocyanate method. Expression of specific mRNAs was determined by ribonuclease protection assay using cRNA probes directed against: ACTH-R; the steroid enzymes side-chain cleavage (P450scc), 3β-hydroxysteroid dehydrogenase (3β-HSD), 17 α-hydroxylase (P450c17) and 21β-hydroxylase (P450c21); and β-actin. Ratios of mRNA expression to β-actin mRNA expression (arbitrary units) were calculated to correct for differences in RNA quality between samples. The concentration (mean SEM) of immunoreactive cortisol in fetal plasma was greater after ACTH infusion than after vehicle infusion (47 3 v. 13 2 ng mL–1 respectively; (P<0.001). Adrenal expression of P450scc and P450c21 mRNA increased after ACTH infusion (P<0.05), whereas expression of P450c17 and 3β-HSD mRNA was unchanged. There was no difference in ACTH-R mRNA expression between ACTH- and vehicle-infused fetuses (254 48 v. 305 76 arbitrary units respectively). It was concluded that ACTH is able to increase plasma cortisol concentrations in the sheep fetus by up-regulating cortisol synthesis in the adrenal gland, but that in vivo this does not require up-regulation of ACTH-R mRNA.

scholarly journals Comprehensive in situ mapping of human cortical transcriptomic cell types

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Christoffer Mattsson Langseth ◽  
Daniel Gyllborg ◽  
Jeremy A. Miller ◽  
Jennie L. Close ◽  
Brian Long ◽  
...  
Keyword(s):  
Brain Function ◽  
Cortical Cell ◽  
Cell Types ◽  
Cell Type ◽  
Cortical Cells ◽  
Human Cortex ◽  
Single Nucleus ◽  
Genetic Signatures ◽  
Cell Typing

AbstractThe ability to spatially resolve the cellular architecture of human cortical cell types over informative areas is essential to understanding brain function. We combined in situ sequencing gene expression data and single-nucleus RNA-sequencing cell type definitions to spatially map cells in sections of the human cortex via probabilistic cell typing. We mapped and classified a total of 59,816 cells into all 75 previously defined subtypes to create a first spatial atlas of human cortical cells in their native position, their abundances and genetic signatures. We also examined the precise within- and across-layer distributions of all the cell types and provide a resource for the cell atlas community. The abundances and locations presented here could serve as a reference for further studies, that include human brain tissues and disease applications at the cell type level.

scholarly journals Comprehensive in situ mapping of human cortical transcriptomic cell types

2021 ◽  
Author(s):  
Christoffer Mattsson Langseth ◽  
Daniel Gyllborg ◽  
Jeremy A. Miller ◽  
Jennie L. Close ◽  
Brian Long ◽  
...  
Keyword(s):  
Brain Function ◽  
Cortical Cell ◽  
Cell Types ◽  
Expression Data ◽  
Cortical Cells ◽  
Human Cortex ◽  
Single Nucleus ◽  
Genetic Signatures ◽  
Cell Typing

The ability to spatially resolve the cellular architecture of human cortical cell types over informative areas is essential to understanding brain function. We combined in situ sequencing gene expression data and single-nucleus RNA-sequencing cell type definitions to spatially map cells in sections of the human cortex via probabilistic cell typing. We mapped and classified a total of 59,816 cells into all 75 previously defined subtypes to create a first spatial atlas of human cortical cells in their native position, their abundances and genetic signatures.

Ultrastructural Cytopiasmic Changes of Adrenal Cortex During Pregnancy

1969 ◽  
Vol 27 ◽  
pp. 298-299
Author(s):  
T. M. Murad ◽  
Karen Israel ◽  
Jack C. Geer
Keyword(s):  
Adrenal Gland ◽  
Steroid Hormones ◽  
Adrenal Cortex ◽  
Lipid Droplets ◽  
Plasma Cholesterol ◽  
Adrenal Steroids ◽  
Dynamic Changes ◽  
Cortical Cells ◽  
Acetyl Coenzyme A ◽  
Adrenal Cortical Cells

Adrenal steroids are normally synthesized from acetyl coenzyme A via cholesterol. Cholesterol is also shown to enter the adrenal gland and to be localized in the lipid droplets of the adrenal cortical cells. Both pregnenolone and progesterone act as intermediates in the conversion of cholesterol into steroid hormones. During pregnancy an increased level of plasma cholesterol is known to be associated with an increase of the adrenal corticoid and progesterone. The present study is designed to demonstrate whether the adrenal cortical cells show any dynamic changes during pregnancy.

FINE STRUCTURE IN CELLS OF PEA AND WHEAT EMBRYOS

1959 ◽  
Vol 37 (1) ◽  
pp. 65-72 ◽  
Author(s):  
G. Setterfield ◽  
H. Stern ◽  
F. B. Johnston
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membranes ◽  
Osmic Acid ◽  
Dense Granules ◽  
Cytoplasmic Bodies ◽  
Wheat Embryos ◽  
Electron Microscopes ◽  
Cell Fractions ◽  
Isolated Cell

To provide a basis for relating biochemical findings on isolated cell fractions to cytological structure in situ, embryos of pea and wheat were fixed with osmic acid, sectioned, and observed in phase-contrast and electron microscopes. The nuclei of all cells were similar, showing nuclear membranes, chromosomes, and prominent nucleoli. The cytoplasm contained highly developed structure which presumably reflected the incipient growth condition of the cells. Several cytoplasmic components were common to both embryos: small dense granules, endoplasmic reticulum, mitochondria, presumed proplastids, amyloplasts, irregular bodies, plasma membranes, and plasmodesmata. The small dense granules, presumably ribonucleoprotein particles, occurred profusely, both free and in association with extensively developed endoplasmic reticulum. These particles are probably responsible for the microsomal fractions obtainable from embryos and seedlings. The mitochondria were usually relatively small (0.25−0.5 μ diameter) although groups of very long (5 μ) ones were occasionally found. Bodies resembling mitochondria in size and shape, but lacking cristae, were present and represent either immature mitochondria or proplastids. Reserve material occurred as starch in structurally complex amyloplasts and possibly as protein in the irregular bodies. In addition to these structures cells of the wheat embryos remote from the meristems contained prominent cytoplasmic bodies classified as "dense" and "thick-walled". The dense bodies probably represent stored lipids while the significance of the thick-walled bodies, which showed a variety of forms, is unknown.

Computing with Self-Excitatory Cliques: A Model and an Application to Hyperacuity-Scale Computation in Visual Cortex

1999 ◽  
Vol 11 (1) ◽  
pp. 21-66 ◽  
Author(s):  
Douglas A. Miller ◽  
Steven W. Zucker
Keyword(s):  
Visual Processing ◽  
Network Architecture ◽  
Early Stage ◽  
Cortical Cell ◽  
Pyramidal Cells ◽  
Direct Calculation ◽  
Formal Theory ◽  
Cortical Cells ◽  
Cell Counts ◽  
Spatiotemporal Response

We present a model of visual computation based on tightly inter-connected cliques of pyramidal cells. It leads to a formal theory of cell assemblies, a specific relationship between correlated firing patterns and abstract functionality, and a direct calculation relating estimates of cortical cell counts to orientation hyperacuity. Our network architecture is unique in that (1) it supports a mode of computation that is both reliable and efficent; (2) the current-spike relations are modeled as an analog dynamical system in which the requisite computations can take place on the time scale required for an early stage of visual processing; and (3) the dynamics are triggered by the spatiotemporal response of cortical cells. This final point could explain why moving stimuli improve vernier sensitivity.

scholarly journals Altered folate binding protein expression and folate delivery are associated with congenital hydrocephalus in the hydrocephalic Texas rat

2018 ◽  
Vol 39 (10) ◽  
pp. 2061-2073 ◽  
Author(s):  
Alicia Requena Jimenez ◽  
Naila Naz ◽  
Jaleel A Miyan
Keyword(s):  
Folate Receptor ◽  
Cortical Cell ◽  
Regulatory Function ◽  
Folate Binding Protein ◽  
In Vitro Proliferation ◽  
Cycle Arrest ◽  
Csf Levels ◽  
And Function

Hydrocephalus (HC) is an imbalance in cerebrospinal fluid (CSF) secretion/absorption resulting in fluid accumulation within the brain with consequential pathophysiology. Our research has identified a unique cerebral folate system in which depletion of CSF 10-formyl-tetrahydrofolate-dehydrogenase (FDH) is associated with cortical progenitor cell-cycle arrest in hydrocephalic Texas (H-Tx) rats. We used tissue culture, immunohistochemistry, in-situ PCR and RT-PCR and found that the in-vitro proliferation of arachnoid cells is highly folate-dependent with exacerbated proliferation occurring in hydrocephalic CSF that has low FDH but high folate-receptor-alpha (FRα) and folate. Adding FDH to this CSF prevented aberrant proliferation indicating a regulatory function of FDH on CSF folate concentration. Arachnoid cells have no detectable mRNA for FRα or FDH, but FDH mRNA is found in the choroid plexus (CP) and CSF microvesicles. Co-localization of FDH, FRα and folate suggests important functions of FDH in cerebral folate transport, buffering and function. In conclusion, abnormal CSF levels of FDH, FRα and folate inhibit cortical cell proliferation but allow uncontrolled arachnoid cell division that should increase fluid absorption by increasing the arachnoid although this fails in the hydrocephalic brain. FDH appears to buffer available folate to control arachnoid proliferation and function.

Early Periderm Ontogeny in Fraxinuspennsylvanica, Ailanthusaltissima, Robiniapseudoacacia, and Pinusresinosa, Seedlings

1972 ◽  
Vol 2 (2) ◽  
pp. 135-143 ◽  
Author(s):  
G. A. Borger ◽  
T. T. Kozlowski
Keyword(s):  
Cell Layer ◽  
Cortical Cell ◽  
Cortical Cells ◽  
Mother Cells

The subepidermal cell layer was the site of origin of the first periderm in the hypocotyl and internodes of Fraxinuspennsylvanica and Ailanthusaltissima. In the hypocotyl of Robiniapsendoacacia, the first periderm arose in cortical cells near the phloem; in the internodes it originated in the subepidermal, second, or third cortical cell layer. The outermost cell layer of the pericycle gave rise to the first periderm in the hypocotyl of Pinusresinosa. In all four species, periderm appeared first near the base of the hypocotyl and developed acropetally. In A. altissima and R. pseudoaeacia, phellem mother cells were cut off by the phellogen. These subsequently divided to produce phellem cells. In F. pennsylvanica and P. resinosa, phellem cells were produced directly from the phellogen.

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