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Sensitization
Sensitization is a non-associative learning process in which repeated administration of a stimulus results in the progressive amplification of a response. Sensitization often is characterized by an enhancement of response to a whole class of stimuli in addition to the one that is repeated. For example, repetition of a painful stimulus may make one more responsive to a loud noise. History Eric Kandel was one of the first to study the neural basis of sensitization, conducting experiments in the 1960s and 1970s on the gill withdrawal reflex of the seaslug '' Aplysia''. Kandel and his colleagues first habituated the reflex, weakening the response by repeatedly touching the animal's siphon. They then paired noxious electrical stimulus to the tail with a touch to the siphon, causing the gill withdrawal response to reappear. After this sensitization, a light touch to the siphon alone produced a strong gill withdrawal response, and this sensitization effect lasted for several days. (Aft ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reward Cross-sensitization
Addiction is a neuropsychological disorder characterized by a persistent and intense urge to engage in certain behaviors, one of which is the usage of a drug, despite substantial harm and other negative consequences. Repetitive drug use often alters brain function in ways that perpetuate craving, and weakens (but does not completely negate) self-control. This phenomenon – drugs reshaping brain function – has led to an understanding of addiction as a brain disorder with a complex variety of psychosocial as well as neurobiological (and thus involuntary) factors that are implicated in addiction's development. Classic signs of addiction include compulsive engagement in rewarding stimuli, ''preoccupation'' with substances or behavior, and continued use despite negative consequences. Habits and patterns associated with addiction are typically characterized by immediate gratification (short-term reward), coupled with delayed deleterious effects (long-term costs). Examples o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reward Sensitization
Addiction is a neuropsychological disorder characterized by a persistent and intense urge to engage in certain behaviors, one of which is the usage of a drug, despite substantial harm and other negative consequences. Repetitive drug use often alters brain function in ways that perpetuate craving, and weakens (but does not completely negate) self-control. This phenomenon – drugs reshaping brain function – has led to an understanding of addiction as a brain disorder with a complex variety of psychosocial as well as neurobiological (and thus involuntary) factors that are implicated in addiction's development. Classic signs of addiction include compulsive engagement in rewarding stimuli, ''preoccupation'' with substances or behavior, and continued use despite negative consequences. Habits and patterns associated with addiction are typically characterized by immediate gratification (short-term reward), coupled with delayed deleterious effects (long-term costs). Examples ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Addictive Drug
Addiction is a neuropsychological disorder characterized by a persistent and intense urge to engage in certain behaviors, one of which is the usage of a drug, despite substantial harm and other negative consequences. Repetitive drug use often alters brain function in ways that perpetuate craving, and weakens (but does not completely negate) self-control. This phenomenon – drugs reshaping brain function – has led to an understanding of addiction as a brain disorder with a complex variety of psychosocial as well as neurobiological (and thus involuntary) factors that are implicated in addiction's development. Classic signs of addiction include compulsive engagement in rewarding stimuli, ''preoccupation'' with substances or behavior, and continued use despite negative consequences. Habits and patterns associated with addiction are typically characterized by immediate gratification (short-term reward), coupled with delayed deleterious effects (long-term costs). Examples ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Behavioral Sensitization
Addiction is a neuropsychological disorder characterized by a persistent and intense urge to engage in certain behaviors, one of which is the usage of a drug, despite substantial harm and other negative consequences. Repetitive drug use often alters brain function in ways that perpetuate craving, and weakens (but does not completely negate) self-control. This phenomenon – drugs reshaping brain function – has led to an understanding of addiction as a brain disorder with a complex variety of psychosocial as well as neurobiological (and thus involuntary) factors that are implicated in addiction's development. Classic signs of addiction include compulsive engagement in rewarding stimuli, ''preoccupation'' with substances or behavior, and continued use despite negative consequences. Habits and patterns associated with addiction are typically characterized by immediate gratification (short-term reward), coupled with delayed deleterious effects (long-term costs). Examples ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drug Addiction
Addiction is a neuropsychological disorder characterized by a persistent and intense urge to engage in certain behaviors, one of which is the usage of a drug, despite substantial harm and other negative consequences. Repetitive drug use often alters Brain#Function, brain function in ways that perpetuate Craving (withdrawal), craving, and weakens (but does not completely negate) self-control. This phenomenon – drugs Neuroplasticity, reshaping Human brain, brain function – has led to an understanding of addiction as a brain disorder with a complex variety of Social psychology, psychosocial as well as Neuroscience, neurobiological (and thus involuntary) factors that are implicated in addiction's development. Classic signs of addiction include Compulsive behavior, compulsive engagement in Reward system, rewarding stimuli, ''preoccupation'' with substances or behavior, and continued use despite negative consequences. Habits and patterns associated with addiction are typically ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Learning
Learning is the process of acquiring new understanding, knowledge, behaviors, skills, values, attitudes, and preferences. The ability to learn is possessed by humans, animals, and some machines; there is also evidence for some kind of learning in certain plants. Some learning is immediate, induced by a single event (e.g. being burned by a hot stove), but much skill and knowledge accumulate from repeated experiences. The changes induced by learning often last a lifetime, and it is hard to distinguish learned material that seems to be "lost" from that which cannot be retrieved. Human learning starts at birth (it might even start before in terms of an embryo's need for both interaction with, and freedom within its environment within the womb.) and continues until death as a consequence of ongoing interactions between people and their environment. The nature and processes involved in learning are studied in many established fields (including educational psychology, neurop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drug Sensitization
Reverse tolerance or drug sensitization is a pharmacological phenomenon describing subjects' increased reaction (positive or negative) to a drug following its repeated use. Not all drugs are subject to reverse tolerance. This is the opposite of drug tolerance, in which the effect or the subject's reaction decreases following its repeated use. The two notions are not incompatible, and tolerance may sometimes lead to reverse tolerance. For example, heavy drinkers initially develop tolerance to alcohol, requiring them to drink larger amounts to achieve a similar effect, but as excessive drinking can cause liver damage, this can then put this group at risk of intoxication when drinking even very small amounts of alcohol. Sensitization, a form of reverse tolerance, develops rapidly to the positive, euphoric effects of alcohol, but not to the physical effects, such as sedation and respiratory depression, which diminish with prolonged use. This sensitization does not occur, however, wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drug Tolerance
Drug tolerance or drug insensitivity is a pharmacological concept describing subjects' reduced reaction to a drug following its repeated use. Increasing its dosage may re-amplify the drug's effects; however, this may accelerate tolerance, further reducing the drug's effects. Drug tolerance is indicative of drug use but is not necessarily associated with drug dependence or addiction. The process of tolerance development is reversible (e.g., through a drug holiday) and can involve both physiological factors and psychological factors. One may also develop drug tolerance to side effects, in which case tolerance is a desirable characteristic. A medical intervention that has an objective to increase tolerance (e.g., allergen immunotherapy, in which one is exposed to larger and larger amounts of allergen to decrease one's allergic reactions) is called drug desensitization. The opposite concept to drug tolerance is drug reverse tolerance (or drug sensitization), in which case the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gateway Drug Theory
The gateway drug effect (alternatively, stepping-stone theory, escalation hypothesis, or progression hypothesis) is a comprehensive catchphrase for the often observed effect that the use of a psychoactive substance is coupled to an increased probability of the use of further substances. Possible causes are biological alterations in the brain due to the earlier substance exposure and similar attitudes of people who use different substances across different substances (''common liability to addiction''). In 2020, the National Institute on Drug Abuse released a study backing allegations that marijuana is a "gateway" to more dangerous substance use, though not for the majority of people who use substances. A literature review by the United States Department of Justice found no conclusive evidence that the link is causal. Sequence of first-time use General concept The concept of ''gateway drug'' is based on observations that the sequence of first-time use of different drugs is not ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aplysia
''Aplysia'' () is a genus of medium-sized to extremely large sea slugs, specifically sea hares, which are one clade of large sea slugs, marine gastropod mollusks. These benthic herbivorous creatures can become rather large compared with most other mollusks. They graze in tidal and subtidal zones of tropical waters, mostly in the Indo-Pacific Ocean (23 species); but they can also be found in the Atlantic Ocean (12 species), with a few species occurring in the Mediterranean. ''Aplysia'' species, when threatened, frequently release clouds of ink, it is believed in order to blind the attacker (though they are in fact considered edible by relatively few species). Following the lead of Eric R. Kandel, the genus has been studied as a model organism by neurobiologists, because its gill and siphon withdrawal reflex, as studied in ''Aplysia californica'', is mediated by electrical synapses, which allow several neurons to fire synchronously. This quick neural response is necessary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AMPA Receptor
The α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (also known as AMPA receptor, AMPAR, or quisqualate receptor) is an ionotropic transmembrane receptor for glutamate (iGluR) that mediates fast synaptic transmission in the central nervous system (CNS). It has been traditionally classified as a non-NMDA-type receptor, along with the kainate receptor. Its name is derived from its ability to be activated by the artificial glutamate analog AMPA. The receptor was first named the "quisqualate receptor" by Watkins and colleagues after a naturally occurring agonist quisqualate and was only later given the label "AMPA receptor" after the selective agonist developed by Tage Honore and colleagues at the Royal Danish School of Pharmacy in Copenhagen. The ''GRIA2''-encoded AMPA receptor ligand binding core (GluA2 LBD) was the first glutamate receptor ion channel domain to be crystallized. Structure and function Subunit composition AMPARs are composed of four types of subun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesolimbic
The mesolimbic pathway, sometimes referred to as the reward pathway, is a dopaminergic pathway in the brain. The pathway connects the ventral tegmental area in the midbrain to the ventral striatum of the basal ganglia in the forebrain. The ventral striatum includes the nucleus accumbens and the olfactory tubercle. The release of dopamine from the mesolimbic pathway into the nucleus accumbens regulates incentive salience (e.g. motivation and desire for rewarding stimuli) and facilitates reinforcement and reward-related motor function learning; it may also play a role in the subjective perception of pleasure. The dysregulation of the mesolimbic pathway and its output neurons in the nucleus accumbens plays a significant role in the development and maintenance of an addiction. Anatomy The mesolimbic pathway is a collection of dopaminergic (i.e., dopamine-releasing) neurons that project from the ventral tegmental area (VTA) to the ventral striatum, which includes the nucleus accumben ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
