|
Normal Brain Aging
Aging of the brain is a process of transformation of the brain in older age, including changes all individuals experience and those of illness (including unrecognised illness). Usually this refers to humans. Since life extension is only pertinent if accompanied by health span extension, and, more importantly, by preserving brain health and cognition, finding rejuvenating approaches that act simultaneously in peripheral tissues and in brain function is a key strategy for development of rejuvenating technology. Aging is a major risk factor for most common neurodegenerative diseases, including mild cognitive impairment, dementias including Alzheimer's disease, cerebrovascular disease, Parkinson's disease, and Lou Gehrig's disease. While much research has focused on diseases of aging, there are few informative studies on the molecular biology of the aging brain (usually spelled ageing brain in British English) in the absence of neurodegenerative disease or the neuropsychological pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aging
Ageing (or aging in American English) is the process of becoming Old age, older until death. The term refers mainly to humans, many other animals, and fungi; whereas for example, bacteria, perennial plants and some simple animals are potentially biologically immortal. In a broader sense, ageing can refer to single cells within an organism which have Cellular senescence, ceased dividing, or to the Population ageing, population of a species. In humans, ageing represents the accumulation of changes in a human being over time and can encompass physical, psychological, and social changes. Reaction time, for example, may slow with age, while memories and general knowledge typically increase. Of the roughly 150,000 people who die each day across the globe, about two-thirds die from age-related causes. Current Theory of aging, ageing theories are assigned to the damage concept, whereby the accumulation of damage (such as DNA oxidation) may cause biological systems to fail, or to the p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Model Organism
A model organism is a non-human species that is extensively studied to understand particular biological phenomena, with the expectation that discoveries made in the model organism will provide insight into the workings of other organisms. Model organisms are widely used to research human disease when human experimentation would be unfeasible or unethical. This strategy is made possible by the common descent of all living organisms, and the conservation of metabolic and developmental pathways and genetic material over the course of evolution. Research using animal models has been central to most of the achievements of modern medicine. It has contributed most of the basic knowledge in fields such as human physiology and biochemistry, and has played significant roles in fields such as neuroscience and infectious disease. The results have included the near- eradication of polio and the development of organ transplantation, and have benefited both humans and animals. From 19 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grey Matter
Grey matter, or gray matter in American English, is a major component of the central nervous system, consisting of neuronal cell bodies, neuropil ( dendrites and unmyelinated axons), glial cells ( astrocytes and oligodendrocytes), synapses, and capillaries. Grey matter is distinguished from white matter in that it contains numerous cell bodies and relatively few myelinated axons, while white matter contains relatively few cell bodies and is composed chiefly of long-range myelinated axons. The colour difference arises mainly from the whiteness of myelin. In living tissue, grey matter actually has a very light grey colour with yellowish or pinkish hues, which come from capillary blood vessels and neuronal cell bodies. Structure Grey matter refers to unmyelinated neurons and other cells of the central nervous system. It is present in the brain, brainstem and cerebellum, and present throughout the spinal cord. Grey matter is distributed at the surface of the cerebral hemisp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ventricular System
In neuroanatomy, the ventricular system is a set of four interconnected cavities known as cerebral ventricles in the brain. Within each ventricle is a region of choroid plexus which produces the circulating cerebrospinal fluid (CSF). The ventricular system is continuous with the central canal of the spinal cord from the fourth ventricle, allowing for the flow of CSF to circulate. All of the ventricular system and the central canal of the spinal cord are lined with ependyma, a specialised form of epithelium connected by tight junctions that make up the blood–cerebrospinal fluid barrier. Structure The system comprises four ventricles: * lateral ventricles right and left (one for each hemisphere) * third ventricle * fourth ventricle There are several foramina, openings acting as channels, that connect the ventricles. The interventricular foramina (also called the foramina of Monro) connect the lateral ventricles to the third ventricle through which the cerebrospinal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CT Scan
A computed tomography scan (CT scan), formerly called computed axial tomography scan (CAT scan), is a medical imaging technique used to obtain detailed internal images of the body. The personnel that perform CT scans are called radiographers or radiology technologists. CT scanners use a rotating X-ray tube and a row of detectors placed in a gantry (medical), gantry to measure X-ray Attenuation#Radiography, attenuations by different tissues inside the body. The multiple X-ray measurements taken from different angles are then processed on a computer using tomographic reconstruction algorithms to produce Tomography, tomographic (cross-sectional) images (virtual "slices") of a body. CT scans can be used in patients with metallic implants or pacemakers, for whom magnetic resonance imaging (MRI) is Contraindication, contraindicated. Since its development in the 1970s, CT scanning has proven to be a versatile imaging technique. While CT is most prominently used in medical diagnosis, i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cerebral Cortex
The cerebral cortex, also known as the cerebral mantle, is the outer layer of neural tissue of the cerebrum of the brain in humans and other mammals. It is the largest site of Neuron, neural integration in the central nervous system, and plays a key role in attention, perception, awareness, thought, memory, language, and consciousness. The six-layered neocortex makes up approximately 90% of the Cortex (anatomy), cortex, with the allocortex making up the remainder. The cortex is divided into left and right parts by the longitudinal fissure, which separates the two cerebral hemispheres that are joined beneath the cortex by the corpus callosum and other commissural fibers. In most mammals, apart from small mammals that have small brains, the cerebral cortex is folded, providing a greater surface area in the confined volume of the neurocranium, cranium. Apart from minimising brain and cranial volume, gyrification, cortical folding is crucial for the Neural circuit, brain circuitry ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dopamine
Dopamine (DA, a contraction of 3,4-dihydroxyphenethylamine) is a neuromodulatory molecule that plays several important roles in cells. It is an organic chemical of the catecholamine and phenethylamine families. It is an amine synthesized by removing a carboxyl group from a molecule of its precursor chemical, L-DOPA, which is synthesized in the brain and kidneys. Dopamine is also synthesized in plants and most animals. In the brain, dopamine functions as a neurotransmitter—a chemical released by neurons (nerve cells) to send signals to other nerve cells. The brain includes several distinct dopamine pathways, one of which plays a major role in the motivational component of reward-motivated behavior. The anticipation of most types of rewards increases the level of dopamine in the brain, and many addictive drugs increase dopamine release or block its reuptake into neurons following release. Other brain dopamine pathways are involved in motor control and in controllin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
White Matter
White matter refers to areas of the central nervous system that are mainly made up of myelinated axons, also called Nerve tract, tracts. Long thought to be passive tissue, white matter affects learning and brain functions, modulating the distribution of action potentials, acting as a relay and coordinating communication between different brain regions. White matter is named for its relatively light appearance resulting from the lipid content of myelin. Its white color in prepared specimens is due to its usual preservation in formaldehyde. It appears pinkish-white to the naked eye otherwise, because myelin is composed largely of lipid tissue veined with capillaries. Structure White matter White matter is composed of bundles, which connect various grey matter areas (the locations of nerve cell bodies) of the brain to each other, and carry nerve impulses between neurons. Myelin acts as an insulator, which allows saltatory conduction, electrical signals to jump, rather than cour ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conceptual Model
The term conceptual model refers to any model that is formed after a wikt:concept#Noun, conceptualization or generalization process. Conceptual models are often abstractions of things in the real world, whether physical or social. Semantics, Semantic studies are relevant to various stages of process of concept formation, concept formation. Semantics is fundamentally a study of concepts, the meaning that thinking beings give to various elements of their experience. Overview Concept models and conceptual models The value of a conceptual model is usually directly proportional to how well it corresponds to a past, present, future, actual or potential state of affairs. A concept model (a model of a concept) is quite different because in order to be a good model it need not have this real world correspondence. In artificial intelligence, conceptual models and conceptual graphs are used for building expert systems and knowledge-based systems; here the analysts are concerned to repres ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blausen 0896 Ventricles Brain
Blausen Medical Communications, Inc. (BMC) is the creator and owner of a library of two- and three-dimensional medical and scientific images and animations, a developer of information technology allowing access to that content, and a business focused on licensing and distributing the content. It was founded by Bruce Blausen in Houston, Texas, in 1991, and is privately held. Background Blausen Medical Communications is a privately held company founded by Bruce Blausen in Houston, Texas in 1991. BMC created and owns a library of medical and scientific images and animations, and has developed information technology tools allowing access to the library; as well, it licenses and otherwise works to distribute the content. As of this date, BMC's animation library comprised approximately 1,500 animations and over 27,000 two- and three-dimensional images designed for point-of-care patient education, which could be accessed by consumers or professional caregivers (primarily via hospital o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Senescence
Senescence () or biological aging is the gradual deterioration of Function (biology), functional characteristics in living organisms. Whole organism senescence involves an increase in mortality rate, death rates or a decrease in fecundity with increasing age, at least in the later part of an organism's biological life cycle, life cycle. However, the resulting effects of senescence can be delayed. The 1934 discovery that calorie restriction can Life extension, extend lifespans by 50% in rats, the existence of species having negligible senescence, and the existence of potentially immortal organisms such as members of the genus ''Hydra (genus), Hydra'' have motivated research into Life extension, delaying senescence and thus age-related diseases. Rare human mutations can cause accelerated aging diseases. Environmental Gerontogens, factors may affect aging – for example, overexposure to ultraviolet radiation accelerates skin aging. Different parts of the body may age at different ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
