Faculty Opinions recommendation of Rhythmic opening and closing of vesicles during constitutive exo- and endocytosis in chromaffin cells.

2001 ◽  
Author(s):  
Erwin Neher
Keyword(s):  
Chromaffin Cells ◽  
Opening And Closing

Morphological Observations on the Granule Types in Rabbit Extra-Adrenal Chromaffin Cells.

1975 ◽  
Vol 33 ◽  
pp. 318-319
Author(s):  
Joe A. Mascorro ◽  
Robert D. Yates
Keyword(s):  
Chromaffin Cells ◽  
Sodium Phosphate ◽  
Ganglion Cells ◽  
Ultrastructural Level ◽  
Osmic Acid ◽  
Adrenal Chromaffin Cells ◽  
Potassium Iodate ◽  
Perfusion Fluid ◽  
New Zealand White Rabbits ◽  
Adrenal Chromaffin

Extra-adrenal chromaffin organs (abdominal paraganglia) constitute rich sources of catecholamines. It is believed that these bodies contain norepinephrine exclusively. However, the present workers recently observed epinephrine type granules in para- ganglion cells. This report investigates catecholamine containing granules in rabbit paraganglia at the ultrastructural level.New Zealand white rabbits (150-170 grams) were anesthetized with 50 mg/kg Nembutal (IP) and perfused with 3% glutaraldehyde buffered with 0.2M sodium phosphate, pH 7.3. The retroperitoneal tissue blocks were removed and placed in perfusion fluid for 4 hours. The abdominal paraganglia were dissected from the blocks, diced, washed in phosphate buffer and fixed in 1% osmic acid buffered with phosphate. In other animals, the glutaraldehyde perfused tissue blocks were immersed for 1 hour in 3% glutaraldehyde/2.5% potassium iodate buffered as before. The paraganglia were then diced, separated into two vials and washed in the buffer. A portion of this tissue received osmic acid fixation.

Alleviation of pain and depression by specific neural transplants: Fine structural correlates

1992 ◽  
Vol 50 (2) ◽  
pp. 1066-1067
Author(s):  
George D. Pappas ◽  
Jacqueline Sagen
Keyword(s):  
Opioid Peptides ◽  
Chromaffin Cells ◽  
Pain Sensitivity ◽  
Opioid Peptide ◽  
Local Source ◽  
Pain Models ◽  
Neural Transplants ◽  
Adrenergic Antagonists ◽  
Csf Levels ◽  
Donor Source

We have been interested in the use of neural transplants mainly as a local source of neuroactive substances, rather than as a replacement for damaged neural circuities. In particular, we have been exploring the possibilities of reducing pain by transplants of opioid peptide producing cells, and reducing depression by transplants of monoamine-producing cells. For the past several years, work in our laboratory has demonstrated in both acute and chronic pain models that transplantation of adrenal medullary tissue or isolated chromaffin cells into CNS pain modulatory regions can reduce pain sensitivity in rodents. Chromaffin cells were chosen as donor source since they produce high levels of both opioid peptides and catecholamines, substances which independently, and probably synergistically, reduce pain sensitivity when injected locally into the spinal cord. The analgesia produced by these transplants most likely results from the release of both opioid peptides and catecholamines, since it can be blocked or attenuated by opiate or adrenergic antagonists, respectively. Furthermore, CSF levels of met-enkephalin and catecholamines are increased by the transplants.

Immunogold labeling of the calcium binding protein synexin in isolated adrenal chromaffin granules and chromaffin cells

1990 ◽  
Vol 48 (3) ◽  
pp. 952-953
Author(s):  
Gemma A.J. Kuijpers ◽  
Harvey B. Pollard
Keyword(s):  
Adrenal Medulla ◽  
Calcium Binding ◽  
Chromaffin Cells ◽  
Cell Activation ◽  
Structural Information ◽  
Dependent Manner ◽  
Chromaffin Granules ◽  
Immuno Electron Microscopy ◽  
Ultrathin Sections ◽  
Adrenal Chromaffin

Exocytotic fusion of granules in the adrenal medulla chromaffin cell is triggered by a rise in the concentration of cytosolic Ca2+ upon cell activation. The protein synexin, annexin VII, was originally found in the adrenal medulla and has been shown to cause aggregation and to support fusion of chromaffin granules in a Ca2+-dependent manner. We have previously suggested that synexin may there fore play a role in the exocytotic fusion process. In order to obtain more structural information on synexin, we performed immuno-electron microscopy on frozen ultrathin sections of both isolated chromaffin granules and chromaffin cells.Chromaffin granules were isolated from bovine adrenal medulla, and synexin was isolated from bovine lung. Granules were incubated in the presence or absence of synexin (24 μg per mg granule protein) and Ca2+ (1 mM), which induces maximal granule aggregation, in 0.3M sucrose-40m MMES buffer(pH 6.0). Granules were pelleted, washed twice in buffer without synexin and fixed with 2% glutaraldehyde- 2% para formaldehyde in 0.1 M phosphate buffer (GA/PFA) for 30 min. Chromaffin cells were isolated and cultured for 3-5 days, and washed and incubated in Krebs solution with or without 20 uM nicotine. Cells were fixed 90 sec after on set of stimulation with GA/PFA for 30 min. Fixed granule or cell pellets were washed, infiltrated with 2.3 M sucrose in PBS, mounted and frozen in liquid N2.

Fusion and Fission Processes in Exocytosis: Possible Roles for Synexin and Osmotic Lysis in the Two Events

1980 ◽  
Vol 38 ◽  
pp. 594-597
Author(s):  
H.B. Pollard ◽  
C.E. Creutz ◽  
C.J. Pazoles ◽  
J.H. Scott
Keyword(s):  
Small Molecules ◽  
Chromaffin Cells ◽  
Adrenal Glands ◽  
General Concept ◽  
Extracellular Calcium ◽  
Large Protein ◽  
Granule Membrane ◽  
Osmotic Lysis ◽  
Per Se ◽  
Chemical Evidence

Exocytosis is a general concept describing secretion of enzymes, hormones and transmitters that are otherwise sequestered in intracellular granules. Chemical evidence for this concept was first gathered from studies on chromaffin cells in perfused adrenal glands, in which it was found that granule contents, including both large protein and small molecules such as adrenaline and ATP, were released together while the granule membrane was retained in the cell. A number of exhaustive reviews of this early work have been published and are summarized in Reference 1. The critical experiments demonstrating the importance of extracellular calcium for exocytosis per se were also first performed in this system (2,3), further indicating the substantial service given by chromaffin cells to those interested in secretory phenomena over the years.

UPAYA MENINGKATKAN KOMPETENSI PEDAGOGIK GURU SDN TURUSGEDE DI SEMESTER I TAHUN PELAJARAN 2018/2019 DALAM MEMBUKA DAN MENUTUP PEMBELAJARAN MELALUI SUPERVISI AKADEMIK TEKNIK PENILAIAN DIRI SENDIRI

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Siti Ulfah
Keyword(s):  
Elementary School ◽  
Action Observation ◽  
The Self ◽  
Self Assessment ◽  
Test Technique ◽  
Assessment Technique ◽  
First Semester ◽  
Opening And Closing ◽  
Academic Year ◽  
Learning By Using

The purposes of this reasearch are 1) describing the efforts of increasing the elementary school of Turusgede teachers pedagogic competence at the first semester of 2018/2019 academic year in opening and closing the learning by using the self assessment technique and 2) analysing the increase of the elementary school of Turusgede teachers pedagogic competence at the first semester of 2018/2019 academic year in opening and closing the learning by using the self assessment technique. This research is School Action Research (SAR). This research is taken palce in elementary school of Turusgede, Subdistrict of Rembang, Regency of Rembang. The time of this research is the early-middle first semester of 2018/2019 academic year. The subjects of this research are teachers in the elementary school of Turusgede, Subdistrict of Rembang, Regency of Rembang, consist of twelve teachers. The data of this research is teachers pedagogic competence in opening and closing the learning. The techniques of collecting data are using nontest technique and test technique. The tools of collecting data are using the sheets of observation, camera application on hand phone and the form of self assessment. The technique of analizing data in this research is decriptive comparation. The procedure of this research is using Cycle Model, consist of four steps: planning, action, observation and reflection. Each cycle is going on one week. The results of this research are 1) the academic supervision with self assessment technique is previously sharing the form of self assessment to the subjects of this research, 2) self assessment technique is self assessment according to the next theme and matter, 3) self assessment technique is self assessment after the learning finish and 4) teachers pedagogic competence with self assessment technique is increasing and including good category (B) that according with the result of observation and including very good category (A) that according with the result of self assessment. Key words: Pedagogic, Supervision, Self Assessment Technique.

Signs and symptoms of craniomandibular dysfunction in a population of Spanish children

2018 ◽  
Vol 16 (1) ◽  
pp. 24
Author(s):  
Maria Esperanza Sánchez-Sánchez
Keyword(s):  
Signs And Symptoms ◽  
Permanent Teeth ◽  
Tooth Sensitivity ◽  
Craniomandibular Dysfunction ◽  
Teeth Grinding ◽  
Specific Questionnaire ◽  
Other Hand ◽  
Opening And Closing

The craniomandibular dysfunction (CMD) is a pathology that can appear at early ages. In a sample of 36 childrenresiding in Madrid (Spain), of both sexes, with ages between 7 and 13 years, the prevalence of signs and symptomsof CMD was analyzed. For that purpose, we did a dental and muscular examination, together with temporomandibularjoints, functional and occlusal examination, and completed with a specific questionnaire. The results revealedthat 100% showed some sign or sympthom of CMD. 77,8% of the pacients presented 3 or more CMD signs.The most prevalent were painful muscle palpation (94,4%), together with sliding anteriorly (91,7%), painful jointpalpation (69,4%), wear facets in permanent teeth (41,7%) and altered opening and closing trayectory (38,9%). Onthe other hand, only 38,9% showed any CMD symptom. The most prevalent symptoms were night teeth grinding(27,8%), followed by tooth sensitivity (19,4%) and fullness in the ears (16,7%). We conclude that in our sample,25% presented mild CMD (less that 3 signs or symptoms), 58,3% presented moderate CMD (from 3 to 6 signs orsymptoms) and 16,7% showed severe CMD (more than 6 symptoms). Nevertheless, it’s important to remark thatnone of these pacients came seeking treatment for his CMD and these symptoms were refered only when beingasked. Hence the importance of a comprehensive clinic history to precociously diagnose this pathology and havethe ability to prevent its progression.

Evidence for a single mechanism gating perceptual and long-term memory information into working memory

2020 ◽  
Author(s):  
Sam Verschooren ◽  
Yoav Kessler ◽  
Tobias Egner
Keyword(s):  
Working Memory ◽  
Long Term Memory ◽  
Sources Of Information ◽  
Term Memory ◽  
Source Selection ◽  
Single Mechanism ◽  
Gating Mechanism ◽  
Opening And Closing ◽  
Selection Of

An influential view of working memory (WM) holds that its’ contents are controlled by a selective gating mechanism that allows for relevant perceptual information to enter WM when opened, but shields WM contents from interference when closed. In support of this idea, prior studies using the reference-back paradigm have established behavioral costs for opening and closing the gate between perception and WM. WM also frequently requires input from long-term memory (LTM), but it is currently unknown whether a similar gate controls the selection of LTM representations into WM, and how WM gating of perceptual vs. LTM sources of information relate to each other. To address these key theoretical questions, we devised a novel version of the reference-back paradigm, where participants switched between gating perceptual and LTM information into WM. We observed clear evidence for gate opening and closing costs in both cases. Moreover, the pattern of costs associated with gating and source-switching indicated that perceptual and LTM information is gated into WM via a single gate, and rely on a shared source-selection mechanism. These findings extend current models of WM gating to encompass LTM information, and outline a new functional WM architecture.

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