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Sleep Spindle
Sleep spindles are bursts of neural oscillatory activity that are generated by interplay of the thalamic reticular nucleus (TRN) and other thalamic nuclei during stage 2 NREM sleep in a frequency range of ~11 to 16 Hz (usually 12–14 Hz) with a duration of 0.5 seconds or greater (usually 0.5–1.5 seconds). After generation as an interaction of the TRN neurons and thalamocortical cells, spindles are sustained and relayed to the cortex by thalamo-thalamic and thalamo-cortical feedback loops regulated by both GABAergic and NMDA-receptor mediated glutamatergic neurotransmission. Sleep spindles have been reported (at face value) for all tested mammalian species. Considering animals in which sleep-spindles were studied extensively (and thus excluding results mislead by pseudo-spindlesGottesmann, C. (1996). The transition from slow-wave sleep to paradoxical sleep: evolving facts and concepts of the neurophysiological processes underlying the intermediate stage of sleep. Neu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stage2sleep New
Stage, stages, or staging may refer to: Arts and media Acting * Stage (theatre), a space for the performance of theatrical productions * Theatre, a branch of the performing arts, often referred to as "the stage" * ''The Stage'', a weekly British theatre newspaper * Stages Repertory Theatre, a theatre company in Houston, Texas Music Performers * Stage, an American band featuring Ryan Star Albums * ''Stage'' (David Bowie album), 1978 * ''Stage'' (Great White album), 1995 * ''Stage'' (Keller Williams album), 2004 * ''Stage'', by Mónica Naranjo, 2009 * ''The Stage'' (album), by Avenged Sevenfold, or the title song (see below), 2016 * ''Stages'' (Cassadee Pope album), 2019 * ''Stages'' (Elaine Paige album), 1983 * ''Stages'' (Eric Clapton album), 1993 * ''Stages'' (Jimi Hendrix album), 1991 * ''Stages'' (Josh Groban album), 2015 * ''Stages'' (Melanie C album), 2012 * ''Stages'' (Triumph album), 1985 * ''Stages'' (Vedera album), 2009 * '' Stages: The Lost Album'', b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schizophrenia
Schizophrenia () is a mental disorder characterized variously by hallucinations (typically, Auditory hallucination#Schizophrenia, hearing voices), delusions, thought disorder, disorganized thinking and behavior, and Reduced affect display, flat or inappropriate affect. Symptoms Prodrome, develop gradually and typically begin during young adulthood and rarely resolve. There is no objective diagnostic test; diagnosis is based on observed behavior, a psychiatric history that includes the person's reported experiences, and reports of others familiar with the person. For a diagnosis of schizophrenia, the described symptoms need to have been present for at least six months (according to the DSM-5) or one month (according to the ICD-11). Many people with schizophrenia have other mental disorders, especially mood disorder, mood, anxiety disorder, anxiety, and substance use disorders, substance use disorders, as well as obsessive–compulsive disorder (OCD). About 0.3% to 0.7% of peo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electroencephalography
Electroencephalography (EEG) is a method to record an electrogram of the spontaneous electrical activity of the brain. The biosignal, bio signals detected by EEG have been shown to represent the postsynaptic potentials of pyramidal neurons in the neocortex and allocortex. It is typically non-invasive, with the EEG electrodes placed along the scalp (commonly called "scalp EEG") using the 10–20 system (EEG), International 10–20 system, or variations of it. Electrocorticography, involving surgical placement of electrodes, is sometimes called Electrocorticography, "intracranial EEG". Clinical interpretation of EEG recordings is most often performed by visual inspection of the tracing or quantitative EEG, quantitative EEG analysis. Voltage fluctuations measured by the EEG bioamplifier, bio amplifier and electrodes allow the evaluation of normal Brain activity and meditation, brain activity. As the electrical activity monitored by EEG originates in neurons in the underlying Huma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sleep Physiology
Sleep is a state of reduced mental and physical activity in which consciousness is altered and certain Sensory nervous system, sensory activity is inhibited. During sleep, there is a marked decrease in muscle activity and interactions with the surrounding environment. While sleep differs from wakefulness in terms of the ability to react to Stimulus (physiology), stimuli, it still involves active Human brain, brain patterns, making it more reactive than a coma or disorders of consciousness. Sleep occurs in sleep cycle, repeating periods, during which the body alternates between two distinct modes: rapid eye movement sleep (REM) and Non-rapid eye movement sleep, non-REM sleep. Although REM stands for "rapid eye movement", this mode of sleep has many other aspects, including virtual Rapid eye movement sleep#Muscle, paralysis of the body. Dreams are a succession of images, ideas, emotions, and sensations that usually occur involuntarily in the mind during certain stages of sleep. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Estrogen
Estrogen (also spelled oestrogen in British English; see spelling differences) is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three major endogenous estrogens that have estrogenic hormonal activity: estrone (E1), estradiol (E2), and estriol (E3). Estradiol, an estrane, is the most potent and prevalent. Another estrogen called estetrol (E4) is produced only during pregnancy. Estrogens are synthesized in all vertebrates and some insects. Quantitatively, estrogens circulate at lower levels than androgens in both men and women. While estrogen levels are significantly lower in males than in females, estrogens nevertheless have important physiological roles in males. Like all steroid hormones, estrogens readily diffuse across the cell membrane. Once inside the cell, they bind to and activate estrogen receptors (ERs) which in turn modulate the expression of many ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Menstruation
Menstruation (also known as a period, among other colloquial terms) is the regular discharge of blood and Mucous membrane, mucosal tissue from the endometrium, inner lining of the uterus through the vagina. The menstrual cycle is characterized by the rise and fall of hormones. Menstruation is triggered by falling progesterone levels, and is a sign that pregnancy has not occurred. Women use feminine hygiene products to maintain hygiene during menses. The first period, a point in time known as menarche, usually begins during puberty, between the ages of 11 and 13. However, menstruation starting as young as 8 years would still be considered normal. The average age of the first period is generally later in the developing world, and earlier in the developed world. The typical length of time between the first day of one period and the first day of the next is 21 to 45 days in young women; in adults, the range is between 21 and 35 days with the average often cited as 28 days. In the b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Declarative Memory
Explicit memory (or declarative memory) is one of the two main types of Long-term memory, long-term human memory, the other of which is implicit memory. Explicit memory is the Consciousness, conscious, intentional Recall (memory), recollection of factual information, previous experiences, and concepts. This type of memory is dependent upon three processes: acquisition, Memory Consolidation, consolidation, and retrieval. Explicit memory can be divided into two categories: episodic memory, which stores specific Experience, personal experiences, and semantic memory, which stores factual information.Tulving E. 1972. Episodic and semantic memory. In Organization of Memory, ed. E Tulving, W Donaldson, pp. 381–403. New York: Academic Explicit memory requires gradual learning, with multiple presentations of a Stimulus (psychology), stimulus and response. The type of knowledge that is stored in explicit memory is called declarative knowledge. Its counterpart, known as implicit memory, re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epilepsy
Epilepsy is a group of Non-communicable disease, non-communicable Neurological disorder, neurological disorders characterized by a tendency for recurrent, unprovoked Seizure, seizures. A seizure is a sudden burst of abnormal electrical activity in the brain that can cause a variety of symptoms, ranging from brief lapses of awareness or muscle jerks to prolonged convulsions. These episodes can result in physical injuries, either directly, such as broken bones, or through causing accidents. The diagnosis of epilepsy typically requires at least two unprovoked seizures occurring more than 24 hours apart. In some cases, however, it may be diagnosed after a single unprovoked seizure if clinical evidence suggests a high risk of recurrence. Isolated seizures that occur without recurrence risk or are provoked by identifiable causes are not considered indicative of epilepsy. The underlying cause is often unknown, but epilepsy can result from brain injury, stroke, infections, Brain tumor, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prion
A prion () is a Proteinopathy, misfolded protein that induces misfolding in normal variants of the same protein, leading to cellular death. Prions are responsible for prion diseases, known as transmissible spongiform encephalopathy (TSEs), which are fatal and transmissible neurodegenerative diseases affecting both humans and animals. These proteins can misfold sporadically, due to genetic mutations, or by exposure to an already misfolded protein, leading to an abnormal Protein tertiary structure, three-dimensional structure that can propagate misfolding in other proteins. The term ''prion'' comes from "proteinaceous infectious particle". Unlike other infectious agents such as viruses, bacteria, and fungi, prions do not contain nucleic acids (DNA or RNA). Prions are mainly twisted Protein isoform, isoforms of the major prion protein (PrP), a naturally occurring protein with an uncertain function. They are the hypothesized cause of various transmissible spongiform encephalopath ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Familial Fatal Insomnia
Fatal insomnia is an extremely rare neurodegenerative prion disease that results in trouble sleeping as its hallmark symptom. The majority of cases are familial (fatal familial insomnia FI, stemming from a mutation in the ''PRNP'' gene, with the remainder of cases occurring sporadically (sporadic fatal insomnia FI. The problems with sleeping typically start out gradually and worsen over time. Eventually, the patient will succumb to total insomnia (''agrypnia excitata''), most often leading to other symptoms such as speech problems, coordination problems, and dementia. It results in death within a few months to a few years, and there is no known disease-modifying treatment. Signs and symptoms The disease has four stages: # Characterized by worsening insomnia, resulting in panic attacks, paranoia, and phobias. This stage lasts for about four months. # Hallucinations and panic attacks become noticeable, continuing for about five months. # Complete inability to sleep is foll ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neural Oscillation
Neural oscillations, or brainwaves, are rhythmic or repetitive patterns of neural activity in the central nervous system. Neural tissue can generate oscillatory activity in many ways, driven either by mechanisms within individual neurons or by interactions between neurons. In individual neurons, oscillations can appear either as oscillations in membrane potential or as rhythmic patterns of action potentials, which then produce oscillatory activation of post-synaptic neurons. At the level of neural ensembles, synchronized activity of large numbers of neurons can give rise to macroscopic oscillations, which can be observed in an electroencephalogram. Oscillatory activity in groups of neurons generally arises from feedback connections between the neurons that result in the synchronization of their firing patterns. The interaction between neurons can give rise to oscillations at a different frequency than the firing frequency of individual neurons. A well-known example of macros ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
