Improved Method for Isolating Synaptosomes from 11 Regions of One Rat Brain: Electron Microscopic and Biochemical Characterization and Use in the Study of Drug Effects on Nerve Terminal ?-Aminobutyric Acid in Vivo

1985 ◽  
Vol 45 (3) ◽  
pp. 879-889 ◽  
Author(s):  
Wolfgang Löscher ◽  
Gerhard Böhme ◽  
Frank Müller ◽  
Sonia Pagliusi
Keyword(s):  
Rat Brain ◽  
Nerve Terminal ◽  
Biochemical Characterization ◽  
Drug Effects ◽  
Aminobutyric Acid ◽  
Improved Method ◽  
Electron Microscopic

FURTHER STUDIES ON THE BINDING OF γ-AMINOBUTYRIC ACID BY BRAIN

1967 ◽  
Vol 45 (12) ◽  
pp. 1795-1807 ◽  
Author(s):  
Paula Strasberg ◽  
K. A. C. Elliott
Keyword(s):  
Rat Brain ◽  
Mitochondrial Fraction ◽  
Sodium Ion ◽  
The Other ◽  
Aminobutyric Acid ◽  
Sodium Ions ◽  
Ninhydrin Reaction ◽  
Gaba Content

Factors which can interfere with the paper chromatographic – ninhydrin method for determining γ-aminobutyric acid (GABA) are described. The GABA–ninhydrin reaction does not involve loss of CO2. GABA that is occluded in subcellular particles in plain sucrose homogenates of rat brain does not readily exchange with radioactive GABA in solution. The relevant particles are found mostly in the "mitochondrial fraction". These particles deteriorate with time and manipulations, and tend to lose much of their GABA content. The presence of sodium (but not of potassium, calcium, or magnesium) in the suspending medium allows considerably more GABA to be bound. The extra bound GABA is exchangeable with free labelled GABA. Sodium also promotes some exchange between free and occluded GABA. It is concluded from the present and previous results that in brain in vivo very little GABA exists in a freely diffusing situation. There are two forms of bound GABA. One of these is an occluded or storage form which does not readily exchange with free GABA though exchange is to some extent promoted by sodium ions. The other is a form which occurs only in the presence of sodium ion and is freely exchangeable with GABA in solution.

scholarly journals Colocalization of microtubule-associated protein 1A and microtubule-associated protein 2 on neuronal microtubules in situ revealed with double-label immunoelectron microscopy.

1987 ◽  
Vol 104 (6) ◽  
pp. 1575-1578 ◽  
Author(s):  
Y Shiomura ◽  
N Hirokawa
Keyword(s):  
Rat Brain ◽  
Immunoelectron Microscopy ◽  
Electron Microscopic ◽  
Gold Particles ◽  
Rabbit Polyclonal Antibody ◽  
Double Label ◽  
Cross Bridges ◽  
Secondary Antibodies

Microtubule-associated protein 1A (MAP1A) and microtubule-associated protein 2 (MAP2) were shown to be colocalized on the same microtubules (MTs) within neuronal cytoskeletons by double-label immunoelectron microscopy. To investigate the electron microscopic disposition of MAP1A and MAP2 and their relationship to MTs in vivo, and to determine whether there are different subsets of MTs which specifically bind either MAP1 or MAP2, we employed a double-label immunogold procedure on rat cerebella using mouse monoclonal antibody against rat brain MAP1A and affinity-purified rabbit polyclonal antibody against rat brain MAP2. MAP1A and MAP2 were identified with secondary antibodies coupled to 10- and 5-nm gold particles, respectively. In Purkinje cell dendrites, both 10- and 5-nm gold particles were observed to be studded on the fuzzy structures attached to the same MTs. Many such structures connected MTs to each other. There was no particular MT which bound either MAP1A or MAP2 alone. Furthermore, there seemed to be no specific regions on MTs where either MAP1A or MAP2 was specifically attached. Hence, we conclude that MAP1A and MAP2 are colocalized on MTs in dendrites and assume that MAP1A and MAP2 have some interrelationship in vivo and that their interactions are responsible for forming the network of cross-bridges between MTs and MTs in neuronal cytoskeletons.

scholarly journals Brain dynein (MAP1C) localizes on both anterogradely and retrogradely transported membranous organelles in vivo.

1990 ◽  
Vol 111 (3) ◽  
pp. 1027-1037 ◽  
Author(s):  
N Hirokawa ◽  
R Sato-Yoshitake ◽  
T Yoshida ◽  
T Kawashima
Keyword(s):  
Nerve Terminal ◽  
Peripheral Nerves ◽  
Molecular Motor ◽  
Retrograde Transport ◽  
Nerve Terminals ◽  
Electron Microscopic ◽  
Electron Microscopic Immunocytochemistry ◽  
Fast Flow

Brain dynein is a microtubule-activated ATPase considered to be a candidate to function as a molecular motor to transport membranous organelles retrogradely in the axon. To determine whether brain dynein really binds to retrogradely transported organelles in vivo and how it is transported to the nerve terminals, we studied the localization of brain dynein in axons after the ligation of peripheral nerves by light and electron microscopic immunocytochemistry using affinity-purified anti-brain dynein antibodies. Different classes of organelles preferentially accumulated at the regions proximal and distal to the ligated part. Interestingly, brain dynein accumulated both at the regions proximal and distal to the ligation sites and localized not only on retrogradely transported membranous organelles but also on anterogradely transported ones. This is the first evidence to show that brain dynein associates with retrogradely transported organelles in vivo and that brain dynein is transported to the nerve terminal by fast flow. This also suggests that there may be some mechanism that activates brain dynein only for retrograde transport.

scholarly journals Receptor-mediated endocytosis of asialoglycoproteins by rat liver hepatocytes: biochemical characterization of the endosomal compartments.

1985 ◽  
Vol 101 (6) ◽  
pp. 2104-2112 ◽  
Author(s):  
D A Wall ◽  
A L Hubbard
Keyword(s):  
Biochemical Characterization ◽  
Temperature Shift ◽  
Rat Hepatocytes ◽  
Cholesterol Content ◽  
Subcellular Fractionation ◽  
In Vivo Studies ◽  
Electron Microscopic ◽  
Coated Pits ◽  
Early Endosomes

The endocytic compartments of the asialoglycoprotein (ASGP) pathway in rat hepatocytes were studied using a combined morphological and biochemical approach in the isolated perfused liver. Use of electron microscopic tracers and a temperature-shift protocol to synchronize ligand entry confirmed the route of ASGP internalization observed in our previous in vivo studies (1) and established conditions under which we could label the contents of successive compartments in the pathway for subcellular fractionation studies. Three endosomal compartments were demonstrated in which ASGPs appear after they enter the cell via coated pits and vesicles but before they reach their site of degradation in lysosomes. These three compartments could be distinguished by their location within the hepatocyte, by their morphological appearance in situ, and by their density in sucrose gradients. The distributions of ASGP receptors, both accessible and latent (revealed by detergent permeabilization), were also examined and compared with that of ligand during subcellular fractionation. Most accessible ASGP receptors co-distributed with conventional plasma membrane markers. However, hepatocytes contain a substantial intracellular pool of latent ASGP binding sites that exceeds the number of cell surface receptors and whose presence is not dependent on ASGP exposure. The distribution of these latent ASGP receptors on sucrose gradients (detected either immunologically or by binding assays) was coincident with that of ligand sequestered within the early endosome compartments. In addition, both early endosomes and the membrane vesicles containing latent ASGP receptors had high cholesterol content, because both shifted markedly in density upon exposure to digitonin.

In vivo conversion of γ-aminobutyric acid and 1,4-butanediol to γ-hydroxybutyric acid in rat brain

1989 ◽  
Vol 38 (24) ◽  
pp. 4375-4380 ◽  
Author(s):  
O.Carter Snead ◽  
Raymond Furner ◽  
Chun Che Liu
Keyword(s):  
Rat Brain ◽  
Aminobutyric Acid ◽  
Hydroxybutyric Acid

Ultrastructural modification of cellular interactions in cancer tumor

1978 ◽  
Vol 36 (2) ◽  
pp. 318-319
Author(s):  
N. P. Dmitrieva
Keyword(s):  
Cancer Cells ◽  
Human Thyroid ◽  
Adjacent Cell ◽  
Main Role ◽  
Cellular Interactions ◽  
Electron Microscopic ◽  
Cancer Tumor ◽  
Normal Human ◽  
Characteristic Features

One of the most characteristic features of cancer cells is their ability to metastasia. It is suggested that the modifications of the structure and properties of cancer cells surfaces play the main role in this process. The present work was aimed at finding out what ultrastructural features apear in tumor in vivo which removal of individual cancer cells from the cell population can provide. For this purpose the cellular interactions in the normal human thyroid and cancer tumor of this gland electron microscopic were studied. The tissues were fixed in osmium tetroxide and were embedded in Araldite-Epon.In normal human thyroid the most common type of intercellular contacts was represented by simple junction formed by the parallelalignment of adjacent cell membranees leaving in between an intermembranes space 15-20 nm filled with electronlucid material (Fig. 1a). Sometimes in the basal part of cells dilatations of the intercellular space 40-50 nm wide were found (Fig. 1a). Here the cell surfaces may form single short microvilli.

The in vivo distribution and dynamics of DNA topoisomerase II in Drosophila embryonic nuclei and chromosomes

1993 ◽  
Vol 51 ◽  
pp. 74-75
Author(s):  
Jason R. Swedlow ◽  
Neil Osheroff ◽  
Tim Karr ◽  
John W. Sedat ◽  
David A. Agard
Keyword(s):  
Topoisomerase Ii ◽  
Biochemical Characterization ◽  
Developmental Cycle ◽  
Dna Topoisomerase Ii ◽  
Chromosomal Distribution ◽  
Dna Topoisomerase ◽  
Ideal System ◽  
Dnase Treatment

DNA topoisomerase II is an ATP-dependent double-stranded DNA strand-passing enzyme that is necessary for full condensation of chromosomes and for complete segregation of sister chromatids at mitosis in vivo and in vitro. Biochemical characterization of chromosomes or nuclei after extraction with high-salt or detergents and DNAse treatment showed that topoisomerase II was a major component of this remnant, termed the chromosome scaffold. The scaffold has been hypothesized to be the structural backbone of the chromosome, so the localization of topoisomerase II to die scaffold suggested that the enzyme might play a structural role in the chromosome. However, topoisomerase II has not been studied in nuclei or chromosomes in vivo. We have monitored the chromosomal distribution of topoisomerase II in vivo during mitosis in the Drosophila embryo. This embryo forms a multi-nucleated syncytial blastoderm early in its developmental cycle. During this time, the embryonic nuclei synchronously progress through 13 mitotic cycles, so this is an ideal system to follow nuclear and chromosomal dynamics.

Cytological changes induced by platinum-thymine in sarcoma-180 cells: Electron microscopy study

1990 ◽  
Vol 48 (3) ◽  
pp. 290-291
Author(s):  
Gustav Ofosu
Keyword(s):  
Mammalian Cells ◽  
Antitumor Agent ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Limiting Factor ◽  
Sarcoma 180 ◽  
Electron Microscopic ◽  
Cytological Changes

Platinum-thymine has been found to be a potent antitumor agent, which is quite soluble in water, and lack nephrotoxicity as the dose-limiting factor. The drug has been shown to interact with DNA and inhibits DNA, RNA and protein synthesis in mammalian cells in vitro. This investigation was undertaken to elucidate the cytotoxic effects of piatinum-thymine on sarcoma-180 cells in vitro ultrastructurally, Sarcoma-180 tumor bearing mice were treated with intraperitoneal injection of platinum-thymine 40mg/kg. A concentration of 60μg/ml dose of platinum-thymine was used in in vitro experiments. Treatments were at varying time intervals of 3, 7 and 21 days for in vivo experiments, and 30, 60 and 120 min., 6, 12, and 24th in vitro. Controls were not treated with platinum-thymine.Electron microscopic analyses of the treated cells in vivo and in vitro showed drastic cytotoxic effect.

Sigma receptors mediate potent neuroprotection in vivo and inhibit neuronal depolarisation and swelling in rat brain slices

2005 ◽  
Vol 25 (1_suppl) ◽  
pp. S468-S468
Author(s):  
Jennifer K Callaway ◽  
Christine Molnar ◽  
Song T Yao ◽  
Bevyn Jarrott ◽  
R David Andrew
Keyword(s):  
Rat Brain ◽  
Brain Slices ◽  
Sigma Receptors
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