Defining the functional components of the thalamic gate

2017 ◽  
Author(s):  
Ray Guillery
Keyword(s):  
Higher Order ◽  
The Body ◽  
Body Parts ◽  
Electron Microscopic ◽  
Microscopic Appearance ◽  
Synaptic Inputs ◽  
Electron Microscopic Appearance ◽  
Subcortical Regions ◽  
Functional Components ◽  
The Brain

This chapter starts by summarizing the electron microscopic appearance of the retinogeniculate axons and their immediate environment. These form the functional components of the visual input to the thalamic gate. I then look at evidence that all major thalamic relay nuclei have a shared structure produced by a shared developmental and evolutionary origin. Each nucleus receives a small proportion of its synaptic inputs (<10%) for relay to the cortex; these are the drivers. Drivers are topographically organized with the topography representing body parts, sensory space, or parts of the brain. Some drivers come from sensory pathways or from subcortical regions of the brain, and these innervate first-order thalamic relays; another, major part of the thalamus receives its drivers from the cerebral cortex itself, and these form the higher-order relays to the cortex. These higher-order corticothalamic inputs are crucial for understanding cortical processing. A large proportion of synaptic inputs (>90%) are not relayed to the cortex and are classifiable as modulators. They contribute to controlling the gate. Some modulators match the topography of the drivers, thus relating to the parts of the body and the world; others do not show this specificity and have more global actions.

scholarly journals Scanning electron microscopic observation of the infection process of a Metarhizium strain Ma6 highly pathogenic to Phyllotreta striolata

2018 ◽  
Author(s):  
Jianyu Li ◽  
Mengzhu Shi ◽  
Yuechao He ◽  
Jianwei Fu ◽  
Lizhen Zheng
Keyword(s):  
Body Surface ◽  
Electron Microscopic Observation ◽  
Infection Process ◽  
The Body ◽  
Body Parts ◽  
Pathogenic Microorganisms ◽  
Electron Microscopic ◽  
Highly Pathogenic ◽  
Phyllotreta Striolata ◽  
Scanning Electron

Background. Phyllotreta striolata is a worldwide pest that harms cruciferous vegetables. The use of pathogenic microorganisms to control pests is an important means of biological control. Using pathogenic microorganisms to prevent and control P. striolata has rarely been reported. Methods. In this study, the infection process of a Metarhizium strain highly pathogenic to P. striolata was observed by stereomicroscopyand scanning electron microscopy (SEM). Results.The results showed that the attachment of Metarhizium strain Ma6 to the body surface varied; the conidia distribution was greatest in the tibia of the posterior leg with thick bristles and in the intersegmental abdominal membrane, and the spore distribution occurred least in the smooth and hard portions of the insect’s body. At the start of the infection, Metarhizium strain Ma6 generally grew from the body parts with gaps or connecting spaces such as mouthparts and the thoracic leg base and joints, then the spores germinated with germ tubes and penetration peg, and the penetration peg penetrated the body surface. Ten days after inoculation, the mycelia divided into conidia, and many mycelia and spores covered the entire adult insect’s body. Discussion. Spore germination occurred on the 5th day after inoculation, and many hyphae and spores covered the entire adult insect body within 10 days after inoculation. And the invasion into tissue gaps from the weaker areas is more efficient than intruding from the body hard surface. This may be the reason for the Metarhizium strain Ma6’s high virulence. This study preliminarily clarified the infection ability and invasion approach of a Metarhizium strain against P. striolata, providing evidence for evaluating the strain’s insecticidal effect and application prospect.

Kirlian Experimental Analysis and IoT

2021 ◽  
Vol 10 (2) ◽  
pp. 29-43
Author(s):  
Rohit Rastogi ◽  
Mamta Saxena ◽  
Devendra K. Chaturvedi ◽  
Mayank Gupta ◽  
Akshit Rajan Rastogi ◽  
...  
Keyword(s):  
Nervous System ◽  
Energy Levels ◽  
Critical Role ◽  
The Body ◽  
Extensive Literature ◽  
Entire Body ◽  
Body Parts ◽  
Sodium Potassium ◽  
Charged Ions ◽  
The Brain

Our entire body, including the brain and nervous system, works with the help of various kinds of biological stuff which includes positively charged ions of elements like sodium, potassium, and calcium. The different body parts have different energy levels, and by measuring the energy level, we can also measure the fitness of an individual. Moreover, this energy and fitness are directly related to mental health and the signals being transmitted between the brain and other parts of the body. Various activities like walking, talking, eating, and thinking are performed with the help of these transmission signals. Another critical role played by them is that it helps in examining the mechanisms of cells present at various places in the human body and signaling the nervous system and brain if they are properly functioning or not. This manuscript is divided into two parts where, in the first part, it provides the introduction, background, and extensive literature survey on Kirlian experiments to measure the human's organ energy.

Edward George Gray. 11 January 1924 – 14 August 1999

2002 ◽  
Vol 48 ◽  
pp. 151-165
Author(s):  
R.W. Guillery
Keyword(s):  
Nervous System ◽  
Three Dimensional ◽  
Electron Microscopic ◽  
Early Application ◽  
Microscopic Appearance ◽  
Wide Range ◽  
Neural Tissues ◽  
Synaptic Junctions ◽  
The Central Nervous System ◽  
Electron Microscopic Appearance

George Gray was an early contributor to our knowledge of the electron microscopic appearance of the central nervous system. He was skilful with the difficult techniques for preparing the tissues, worked rapidly, and was an astute observer. Sitting with him in the dark, staring at a dim image that George was moving rapidly as he searched for significant detail, could be an exciting experience. He had clear ideas about features that mattered and could quickly relate the two-dimensional electron microscopic images to the three-dimensional neural structures under investigation. He is best known for his detailed and perceptive description of synaptic junctions in the mammalian neocortex, and his name is still linked to two distinct junctional types (Gray's type 1 and Gray's type 2), now recognized as generally distinguishing excitatory from inhibitory junctions. He studied a wide range of neural tissues, played a significant role in the early isolation of ‘synaptosomes’, contributed greatly to the rapid advance of knowledge that accompanied the early application of the electron microscope to neural tissues, and influenced a great many later fine-structural studies of the nervous system.

Multivalent interaction between asialofetuin and plasma membrane preparations from the rat liver

1980 ◽  
Vol 58 (12) ◽  
pp. 1414-1420 ◽  
Author(s):  
Maria T. Debanne ◽  
Erwin Regoeczi ◽  
Mark W. C. Hatton
Keyword(s):  
Rat Liver ◽  
Plasma Membranes ◽  
Binding Capacity ◽  
Theoretical Models ◽  
Underlying Mechanism ◽  
Marker Enzyme ◽  
Electron Microscopic ◽  
Microscopic Appearance ◽  
Wide Range ◽  
Electron Microscopic Appearance

Binding of bovine asialofetuin by rat liver plasma membranes was studied using different techniques for the separation of the free and bound forms of the glycoprotein and also different approaches to measure nonspecific binding. The membrane preparations had the electron microscopic appearance of a mixture of lamellae and vesicles and their lipid:protein ratios and marker enzyme profiles fell within the range of values available from the literature. The binding capacity was approximately 15 pmol of asialofetuin per milligram of membrane protein.Scatchard plots of the values obtained over a wide range of concentrations (4.8–12.6 μg asialofetuin per 30 μg membrane protein) after incubation at 22 °C showed pronounced non-linearity which, in combination with evaluations according to other theoretical models, was referable to heterogeneity of binding. In sharp contrast, after incubation at 4 °C the Scatchard plot was linear. This difference is interpreted as the expression of a functional, rather than a chemical, heterogeneity in asialofetuin binding. The underlying mechanism is thought to be competition of galactose groups for binding sites with the result that the number of bonds varies between the galactose groups of a bound asialofetuin molecule and the hepatic lectin, depending on the concentration of the glycoprotein in the incubation mixture.

scholarly journals REVERSIBLE AND IRREVERSIBLE CHANGES IN THE FINE STRUCTURE OF NERVOUS TISSUE DURING OXYGEN AND GLUCOSE DEPRIVATION

1965 ◽  
Vol 26 (3) ◽  
pp. 885-909 ◽  
Author(s):  
Henry deF. Webster ◽  
Adelbert Ames
Keyword(s):  
Synaptic Vesicles ◽  
Glucose Deprivation ◽  
Control Medium ◽  
Electron Microscopic ◽  
Microscopic Appearance ◽  
Oxygen And Glucose Deprivation ◽  
Golgi Membranes ◽  
Electrophysiological Measurements ◽  
Synaptic Changes ◽  
Electron Microscopic Appearance

Rabbit retinas were fixed for electron microscopy immediately after removing the eye and after incubations in a control medium and in three different deprivation media that were identical with the control except for the omission of glucose, oxygen, or both. A systematic comparison was made of the electron microscopic appearance of the different retinas with particular attention to four regions: rod inner segments, rod synapses, bipolar cell bodies, and ganglion cell myelinated axons. Retinas fixed after 1 hour of incubation in the control medium appeared virtually identical with those fixed immediately after ocular removal. Retinas deprived of oxygen and glucose for only 3 minutes showed generalized swelling of mitochondria and alterations in the structure of the synapses with loss of synaptic vesicles. Extending the combined deprivation caused further mitochondrial swelling and synaptic changes and also led to progressive swelling of the Golgi membranes and the granular endoplasmic reticulum. All these changes were almost completely reversible for up to 20 minutes but were irreversible by 30 minutes, at which time multiple discontinuities had appeared in cell and organelle membranes. Anoxia alone produced alterations similar to those found after somewhat shorter periods of the combined deprivation, whereas glucose withdrawal produced only minor changes. These electron microscopic results correlate quite well with previously reported electrophysiological measurements.

Sign in / Sign up

Export Citation Format

Share Document