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Neuroscience Of Aging
The neuroscience of aging is the study of the changes in the nervous system that occur with aging. Aging is associated with many changes in the central nervous system, such as mild atrophy of the cortex, which is considered non-pathological. Aging is also associated with many neurological and neurodegenerative diseases, such as amyotrophic lateral sclerosis, dementia, mild cognitive impairment, Parkinson's disease, and Creutzfeldt–Jakob disease. Normal structural and neural changes Neurogenesis occurs very little in adults; it only occurs in the hypothalamus and striatum to a small extent in a process called adult neurogenesis. Environmental enrichment, physical activity and stress (which can stimulate or hinder this process) are key environmental and physiological factors affecting adult neurogenesis. Sensory stimulation, social interactions, and cognitive challenges can describe an enriched environment. Exercising has frequently increased the reproduction of neuronal precurso ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ageing
Ageing (or aging in American English) is the process of becoming 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 ceased dividing, or to the 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 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 programmed ageing concept, whereby the internal processes (e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DNA Oxidation
DNA oxidation is the process of oxidative damage of Deoxyribonucleic Acid, deoxyribonucleic acid. As described in detail by Burrows et al., 8-oxo-2'-deoxyguanosine (8-oxo-dG) is the most common oxidative lesion observed in duplex DNA because guanine has a lower one-electron Redox, reduction potential than the other nucleosides in DNA. The one electron reduction potentials of the nucleosides (in volts versus Standard hydrogen electrode#Relationship between the normal hydrogen electrode (NHE) and the standard hydrogen electrode (SHE), NHE) are guanine 1.29, adenine 1.42, cytosine 1.6 and thymine 1.7. About 1 in 40,000 guanines in the genome are present as 8-oxo-dG under normal conditions. This means that >30,000 8-oxo-dGs may exist at any given time in the genome of a human cell. Another product of DNA oxidation is 8-oxo-dA. 8-oxo-dA occurs at about 1/10 the frequency of 8-oxo-dG. The reduction potential of guanine may be reduced by as much as 50%, depending on the particular ne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Chemotherapeutic Agents
This is a list of chemotherapeutic agents, also known as cytotoxic agents or cytostatic drugs, that are known to be of use in chemotherapy for cancer. This list is organized by type of agent, although the subsections are not necessarily definitive and are subject to revision. Each drug is listed once (at present), though it might fall in more than one subsection. A full alphabetical listing is included after the categorical listing. The agents in this list are often combined into chemotherapy agent for polychemotherapy (combination chemotherapy). For example, the CHOP regimen consists of cyclophosphamide, doxorubicin, vincristine and prednisone. Besides chemotherapy, medical oncology (pharmacotherapy for cancer) includes several noncytotoxic classes of therapy, such as hormonal therapy and targeted therapy (biologic therapy). Those agents are described in the relevant articles. Alkylating agents * Altretamine * Bendamustine * Busulfan * Carboquone * Carmustine * Chlor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha-synuclein
Alpha-synuclein (aSyn) is a protein that in humans is encoded by the ''SNCA'' gene. It is a neuronal protein involved in the regulation of synaptic vesicle trafficking and the release of neurotransmitters. Alpha-synuclein is abundant in the brain, with smaller amounts present in the heart, muscles, and other tissues. Within the brain, it is primarily localized to the axon terminals of presynaptic neurons. There, it interacts with phospholipids and other proteins. Presynaptic terminals release neurotransmitters from specialized compartments called synaptic vesicles, a process essential for neuronal communication and normal brain function. In Parkinson's disease and related synucleinopathies, abnormal, insoluble forms of alpha-synuclein accumulate within neurons as inclusion bodies, inclusions known as Lewy body, Lewy bodies. Mutations in the ''SNCA'' gene are linked to familial forms of Parkinson's disease. During the process of seeded nucleation, alpha-synuclein adopts a cross-be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amyloid Beta
Amyloid beta (Aβ, Abeta or beta-amyloid) denotes peptides of 36–43 amino acids that are the main component of the amyloid plaques found in the brains of people with Alzheimer's disease. The peptides derive from the amyloid-beta precursor protein (APP), which is cleaved by Beta-secretase 1, beta secretase and gamma secretase to yield Aβ in a cholesterol-dependent process and substrate presentation. Both neurons and oligodendrocytes produce and release Aβ in the brain, contributing to formation of amyloid plaques. Aβ molecules can aggregate to form flexible soluble oligomers which may exist in several forms. It is now believed that certain misfolded oligomers (known as "seeds") can induce other Aβ molecules to also take the misfolded oligomeric form, leading to a chain reaction akin to a prion infection. The oligomers are toxic to nerve cells. The other protein implicated in Alzheimer's disease, tau protein, also forms such prion-like misfolded oligomers, and there is some ev ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vascular Dementia
Vascular dementia is dementia caused by a series of strokes. Restricted blood flow due to strokes reduces oxygen and glucose delivery to the brain, causing cell injury and neurological deficits in the affected region. Subtypes of vascular dementia include subcortical vascular dementia, multi-infarct dementia, stroke-related dementia, and mixed dementia. Subcortical vascular dementia occurs from damage to small blood vessels in the brain. Multi-infarct dementia results from a series of small strokes affecting several brain regions. Stroke-related dementia involving successive small strokes causes a more gradual decline in cognition. Dementia may occur when neurodegenerative and cerebrovascular pathologies are mixed, as in susceptible elderly people (75 years and older). Cognitive decline can be traced back to occurrence of successive strokes. ICD-11 lists vascular dementia as ''dementia due to cerebrovascular disease''. DSM-5 lists vascular dementia as either ''major or mild vas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corticobasal Degeneration
Corticobasal degeneration (CBD) is a rare neurodegenerative disease involving the cerebral cortex and the basal ganglia. CBD symptoms typically begin in people from 50 to 70 years of age, and typical survival before death is eight years. It is characterized by marked disorders in movement and cognition, and is classified as one of the Parkinson plus syndromes. Diagnosis is difficult, as symptoms are often similar to those of other disorders, such as Parkinson's disease, progressive supranuclear palsy, and dementia with Lewy bodies, and a definitive diagnosis of CBD can only be made upon neuropathologic examination. Signs and symptoms Because CBD is progressive, a standard set of diagnostic criteria can be used, which is centred on the disease's evolution. Included in these fundamental features are problems with cortical processing, dysfunction of the basal ganglia, and a sudden and detrimental onset. Psychiatric and cognitive dysfunctions, although present in CBD, are much l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dementia With Lewy Bodies
Dementia with Lewy bodies (DLB) is a type of dementia characterized by changes in sleep, behavior change (individual), behavior, cognition, movement, and dysautonomia, regulation of automatic bodily functions. Unlike some other dementias, memory loss may not be an early symptom. The disease progressive disease, worsens over time and is usually diagnosed when cognitive impairment interferes with activities of daily living, normal daily functioning. Together with Parkinson's disease dementia, DLB is one of the two Lewy body dementias. It is a common form of dementia, but the prevalence is not known accurately and many diagnoses are missed. The disease was first described on autopsy by Kenji Kosaka (psychiatrist), Kenji Kosaka in 1976, and he named the condition several years later. REM sleep behavior disorder (RBD)—in which people lose the muscle paralysis (atonia) that normally occurs during Rapid eye movement sleep, REM sleep and act out their dreams—is a core feature. RBD ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frontotemporal Dementia
Frontotemporal dementia (FTD), also called frontotemporal degeneration disease or frontotemporal neurocognitive disorder, encompasses several types of dementia involving the progressive degeneration of the brain's frontal lobe, frontal and temporal lobes. Men and women appear to be equally affected. FTD generally presents as a behavioral or language disorder with gradual onset. Signs and symptoms tend to appear in late adulthood, typically between the ages of 45 and 65, although it can affect people younger or older than this. There is currently no cure or approved symptomatic treatment for FTD, although some Off-label use, off-label drugs and behavioral methods are prescribed. Features of FTD were first described by Arnold Pick between 1892 and 1906. The name ''Pick's disease'' was coined in 1922. This term is now reserved only for the behavioral variant of FTD, in which characteristic Pick bodies and Pick cells are present. These were first described by Alois Alzheimer in 1911. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amyotrophic Lateral Sclerosis
Amyotrophic lateral sclerosis (ALS), also known as motor neuron disease (MND) or—in the United States—Lou Gehrig's disease (LGD), is a rare, Terminal illness, terminal neurodegenerative disease, neurodegenerative disorder that results in the progressive loss of both upper and lower motor neurons that normally control Skeletal muscle, voluntary muscle contraction. ALS is the most common form of the motor neuron diseases. ALS often presents in its early stages with gradual muscle Spasticity, stiffness, Fasciculation, twitches, Muscle weakness, weakness, and Muscle atrophy, wasting. Motor neuron loss typically continues until the abilities to eat, speak, move, and, lastly, breathe are all lost. While only 15% of people with ALS also fully develop frontotemporal dementia, an estimated 50% face at least some minor difficulties with cognitive disorder, thinking and behavior. Depending on which of the aforementioned symptoms develops first, ALS is classified as ''limb-onset'' (b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stroke
Stroke is a medical condition in which poor cerebral circulation, blood flow to a part of the brain causes cell death. There are two main types of stroke: brain ischemia, ischemic, due to lack of blood flow, and intracranial hemorrhage, hemorrhagic, due to bleeding. Both cause parts of the brain to stop functioning properly. Signs and symptoms of stroke may include an hemiplegia, inability to move or feel on one side of the body, receptive aphasia, problems understanding or expressive aphasia, speaking, dizziness, or homonymous hemianopsia, loss of vision to one side. Signs and symptoms often appear soon after the stroke has occurred. If symptoms last less than 24 hours, the stroke is a transient ischemic attack (TIA), also called a mini-stroke. subarachnoid hemorrhage, Hemorrhagic stroke may also be associated with a thunderclap headache, severe headache. The symptoms of stroke can be permanent. Long-term complications may include pneumonia and Urinary incontinence, loss of b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
