Neurotoxin
Encyclopedia
A neurotoxin is a toxin
that acts specifically on nerve cells (neuron
s), usually by interacting with membrane protein
s such as ion channel
s. Some sources are more general, and define the effect of neurotoxins as occurring at nerve tissue. Bungarotoxin
, which is considered a neurotoxin, has its effect at the motor end plate
.
are described as exogenous and include gas
es (such as carbon monoxide
), metals (such as mercury
), liquid
s (ethanol
), and numerous solids. Many neurotoxins are found in plant and animal matter found in nature; for example the neurotoxin aesculin
is found in the horse chestnut (Aesculus hippocastanum), and the California buckeye tree. When exogenous toxins are ingested, the effect on neuron
s is largely dependent on dosage.
glutamate, which, when levels reach too high, can result in excitotoxicity
and cause neuronal death by apoptosis
.
s, scorpion
s, pufferfish
, spider
s, and snake
s can contain many different toxins.
A potent neurotoxin such as batrachotoxin
affects the nervous system by causing depolarization
of nerve and muscle fibers due to increased sodium
ion
permeability
of the excitable cell membrane
.
A very potent neurotoxin is tetrodotoxin
. This chemical acts to block sodium channels
in neurons, preventing action potential
s. This leads to paralysis and eventually death.
Saxitoxin
is also a very potent natural neurotoxin, produced by some strains of marine dinoflagellate
s, cyanobacteria and puffer fish. Saxitoxins bioaccumulate in shellfish and certain finfish. Ingestion of saxitoxin, usually through shellfish contaminated by toxic algal blooms, can result in paralytic shellfish poisoning
. Together with tetrodoxin, saxitoxin has been used in molecular biology to establish the function of the sodium channel. It acts on the voltage-gated sodium channels of nerve cells, preventing normal cellular function and leading to paralysis. The blocking of neuronal sodium channels which occurs in paralytic shellfish poisoning produces a flaccid paralysis
that leaves its victim calm and conscious through the progression of symptoms. Death often occurs from respiratory failure
.
Bungarotoxin
is also a very potent neurotoxin. It binds irreversibly and competitively to the acetylcholine receptor found at the end plate of the neuromuscular junction, causing paralysis, and depending on the dose, can cause respiratory failure and death in the victim
Another very potent neurotoxin is taipoxin
. The toxin causes a gradual reduction to complete stop of evoked and spontaneous release of acetylcholine from motor nerve terminals. If the dose is high enough, the victim can die from asphyxia caused by paralysis of the respiratory muscles.
Botulinum neurotoxins are the most potent natural toxins known(only tested on laboratory mice). They are produced by various toxigenic strains of Clostridium botulinum
and act as metalloproteinases that enter peripheral cholinergic nerve terminals and cleave proteins that are crucial components of the neuroexocytosis apparatus, causing a persistent but reversible inhibition of neurotransmitter release resulting in flaccid muscle paralysis.
s, have been developed for use as chemical weapons.
Toxin
A toxin is a poisonous substance produced within living cells or organisms; man-made substances created by artificial processes are thus excluded...
that acts specifically on nerve cells (neuron
Neuron
A neuron is an electrically excitable cell that processes and transmits information by electrical and chemical signaling. Chemical signaling occurs via synapses, specialized connections with other cells. Neurons connect to each other to form networks. Neurons are the core components of the nervous...
s), usually by interacting with membrane protein
Membrane protein
A membrane protein is a protein molecule that is attached to, or associated with the membrane of a cell or an organelle. More than half of all proteins interact with membranes.-Function:...
s such as ion channel
Ion channel
Ion channels are pore-forming proteins that help establish and control the small voltage gradient across the plasma membrane of cells by allowing the flow of ions down their electrochemical gradient. They are present in the membranes that surround all biological cells...
s. Some sources are more general, and define the effect of neurotoxins as occurring at nerve tissue. Bungarotoxin
Bungarotoxin
α-Bungarotoxin is one of the components of the venom of the elapid snake Taiwanese banded krait . It binds irreversibly and competitively to the acetylcholine receptor found at the neuromuscular junction, causing paralysis, respiratory failure and death in the victim...
, which is considered a neurotoxin, has its effect at the motor end plate
Neuromuscular junction
A neuromuscular junction is the synapse or junction of the axon terminal of a motor neuron with the motor end plate, the highly-excitable region of muscle fiber plasma membrane responsible for initiation of action potentials across the muscle's surface, ultimately causing the muscle to contract...
.
Exogenous
Toxins ingested from the environmentEnvironment (biophysical)
The biophysical environment is the combined modeling of the physical environment and the biological life forms within the environment, and includes all variables, parameters as well as conditions and modes inside the Earth's biosphere. The biophysical environment can be divided into two categories:...
are described as exogenous and include gas
Gas
Gas is one of the three classical states of matter . Near absolute zero, a substance exists as a solid. As heat is added to this substance it melts into a liquid at its melting point , boils into a gas at its boiling point, and if heated high enough would enter a plasma state in which the electrons...
es (such as carbon monoxide
Carbon monoxide
Carbon monoxide , also called carbonous oxide, is a colorless, odorless, and tasteless gas that is slightly lighter than air. It is highly toxic to humans and animals in higher quantities, although it is also produced in normal animal metabolism in low quantities, and is thought to have some normal...
), metals (such as mercury
Mercury (element)
Mercury is a chemical element with the symbol Hg and atomic number 80. It is also known as quicksilver or hydrargyrum...
), liquid
Liquid
Liquid is one of the three classical states of matter . Like a gas, a liquid is able to flow and take the shape of a container. Some liquids resist compression, while others can be compressed. Unlike a gas, a liquid does not disperse to fill every space of a container, and maintains a fairly...
s (ethanol
Ethanol
Ethanol, also called ethyl alcohol, pure alcohol, grain alcohol, or drinking alcohol, is a volatile, flammable, colorless liquid. It is a psychoactive drug and one of the oldest recreational drugs. Best known as the type of alcohol found in alcoholic beverages, it is also used in thermometers, as a...
), and numerous solids. Many neurotoxins are found in plant and animal matter found in nature; for example the neurotoxin aesculin
Aesculin
Aesculin, also rendered Æsculin or Esculin, is a glucoside that naturally occurs in the horse chestnut , California Buckeye and in daphnin ....
is found in the horse chestnut (Aesculus hippocastanum), and the California buckeye tree. When exogenous toxins are ingested, the effect on neuron
Neuron
A neuron is an electrically excitable cell that processes and transmits information by electrical and chemical signaling. Chemical signaling occurs via synapses, specialized connections with other cells. Neurons connect to each other to form networks. Neurons are the core components of the nervous...
s is largely dependent on dosage.
Endogenous
Neurotoxicity also occurs from substances produced within the body, known as endogenous neurotoxins. An example of an endogenous neurotoxin is the primary neurotransmitterNeurotransmitter
Neurotransmitters are endogenous chemicals that transmit signals from a neuron to a target cell across a synapse. Neurotransmitters are packaged into synaptic vesicles clustered beneath the membrane on the presynaptic side of a synapse, and are released into the synaptic cleft, where they bind to...
glutamate, which, when levels reach too high, can result in excitotoxicity
Excitotoxicity
Excitotoxicity is the pathological process by which nerve cells are damaged and killed by excessive stimulation by neurotransmitters such as glutamate and similar substances. This occurs when receptors for the excitatory neurotransmitter glutamate such as the NMDA receptor and AMPA receptor are...
and cause neuronal death by apoptosis
Apoptosis
Apoptosis is the process of programmed cell death that may occur in multicellular organisms. Biochemical events lead to characteristic cell changes and death. These changes include blebbing, cell shrinkage, nuclear fragmentation, chromatin condensation, and chromosomal DNA fragmentation...
.
Venoms
Many of the venoms and other toxins that organisms use in defense against predators are neurotoxins. A common effect is paralysis, which sets in very rapidly. The venom of beeBee
Bees are flying insects closely related to wasps and ants, and are known for their role in pollination and for producing honey and beeswax. Bees are a monophyletic lineage within the superfamily Apoidea, presently classified by the unranked taxon name Anthophila...
s, scorpion
Scorpion
Scorpions are predatory arthropod animals of the order Scorpiones within the class Arachnida. They have eight legs and are easily recognized by the pair of grasping claws and the narrow, segmented tail, often carried in a characteristic forward curve over the back, ending with a venomous stinger...
s, pufferfish
Pufferfish
Tetraodontidae is a family of primarily marine and estuarine fish of the Tetraodontiformes order. The family includes many familiar species which are variously called pufferfish, balloonfish, blowfish, bubblefish, globefish, swellfish, toadfish, toadies, honey toads, sugar toads, and sea squab...
, spider
Spider
Spiders are air-breathing arthropods that have eight legs, and chelicerae with fangs that inject venom. They are the largest order of arachnids and rank seventh in total species diversity among all other groups of organisms...
s, and snake
Snake
Snakes are elongate, legless, carnivorous reptiles of the suborder Serpentes that can be distinguished from legless lizards by their lack of eyelids and external ears. Like all squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales...
s can contain many different toxins.
Channel inhibitors
Many neurotoxins act by affecting voltage-dependent ion channels:| Agent | Channel >- | tetrodotoxin Tetrodotoxin Tetrodotoxin, also known as "tetrodox" and frequently abbreviated as TTX, sometimes colloquially referred to as "zombie powder" by those who practice Vodou, is a potent neurotoxin with no known antidote. There have been successful tests of a possible antidote in mice, but further tests must be... and batrachotoxin Batrachotoxin Batrachotoxins are extremely potent cardiotoxic and neurotoxic steroidal alkaloids found in certain species of frogs , melyrid beetles, and birds... |
>- | potassium channel Potassium channel In the field of cell biology, potassium channels are the most widely distributed type of ion channel and are found in virtually all living organisms. They form potassium-selective pores that span cell membranes... s >- | calciseptine, taicatoxin Taicatoxin Taicatoxin is a snake toxin that blocks voltage-dependent L-type calcium channels and small conductance Ca2+-activated K+ channels. The name taicatoxin is derived from its natural source, the taipan snake, the site of its action, calcium channels, and from its function as a toxin... , calcicludine Calcicludine Calcicludine is a protein toxin from the venom of the green mamba that inhibits high-voltage-activated calcium channels, especially L-type calcium channels.- Source :Calcicludine is a toxin in the venom of the green mamba .... , and PhTx3 |
calcium channel Calcium channel A Calcium channel is an ion channel which displays selective permeability to calcium ions. It is sometimes synonymous as voltage-dependent calcium channel, although there are also ligand-gated calcium channels.-Comparison tables:... s |
A potent neurotoxin such as batrachotoxin
Batrachotoxin
Batrachotoxins are extremely potent cardiotoxic and neurotoxic steroidal alkaloids found in certain species of frogs , melyrid beetles, and birds...
affects the nervous system by causing depolarization
Depolarization
In biology, depolarization is a change in a cell's membrane potential, making it more positive, or less negative. In neurons and some other cells, a large enough depolarization may result in an action potential...
of nerve and muscle fibers due to increased sodium
Sodium
Sodium is a chemical element with the symbol Na and atomic number 11. It is a soft, silvery-white, highly reactive metal and is a member of the alkali metals; its only stable isotope is 23Na. It is an abundant element that exists in numerous minerals, most commonly as sodium chloride...
ion
Ion
An ion is an atom or molecule in which the total number of electrons is not equal to the total number of protons, giving it a net positive or negative electrical charge. The name was given by physicist Michael Faraday for the substances that allow a current to pass between electrodes in a...
permeability
Permeability (fluid)
Permeability in fluid mechanics and the earth sciences is a measure of the ability of a porous material to allow fluids to pass through it.- Units :...
of the excitable cell membrane
Cell membrane
The cell membrane or plasma membrane is a biological membrane that separates the interior of all cells from the outside environment. The cell membrane is selectively permeable to ions and organic molecules and controls the movement of substances in and out of cells. It basically protects the cell...
.
A very potent neurotoxin is tetrodotoxin
Tetrodotoxin
Tetrodotoxin, also known as "tetrodox" and frequently abbreviated as TTX, sometimes colloquially referred to as "zombie powder" by those who practice Vodou, is a potent neurotoxin with no known antidote. There have been successful tests of a possible antidote in mice, but further tests must be...
. This chemical acts to block sodium channels
Sodium channel blocker
Sodium channel blockers are agents that impair conduction of sodium ions through sodium channels.-Extracellular:The following naturally produced substances block sodium channels by binding to and occluding the extracellular pore opening of the channel:...
in neurons, preventing action potential
Action potential
In physiology, an action potential is a short-lasting event in which the electrical membrane potential of a cell rapidly rises and falls, following a consistent trajectory. Action potentials occur in several types of animal cells, called excitable cells, which include neurons, muscle cells, and...
s. This leads to paralysis and eventually death.
Saxitoxin
Saxitoxin
Saxitoxin is a neurotoxin naturally produced by certain species of marine dinoflagellates and cyanobacteria Saxitoxin (STX) is a neurotoxin naturally produced by certain species of marine dinoflagellates (Alexandrium sp., Gymnodinium sp., Pyrodinium sp.) and cyanobacteria Saxitoxin (STX) is a...
is also a very potent natural neurotoxin, produced by some strains of marine dinoflagellate
Dinoflagellate
The dinoflagellates are a large group of flagellate protists. Most are marine plankton, but they are common in fresh water habitats as well. Their populations are distributed depending on temperature, salinity, or depth...
s, cyanobacteria and puffer fish. Saxitoxins bioaccumulate in shellfish and certain finfish. Ingestion of saxitoxin, usually through shellfish contaminated by toxic algal blooms, can result in paralytic shellfish poisoning
Paralytic shellfish poisoning
Paralytic shellfish poisoning is one of the four recognized syndromes of shellfish poisoning, which share some common features and are primarily associated with bivalve mollusks . These shellfish are filter feeders and, therefore, accumulate toxins produced by microscopic algae, such as...
. Together with tetrodoxin, saxitoxin has been used in molecular biology to establish the function of the sodium channel. It acts on the voltage-gated sodium channels of nerve cells, preventing normal cellular function and leading to paralysis. The blocking of neuronal sodium channels which occurs in paralytic shellfish poisoning produces a flaccid paralysis
Flaccid paralysis
Flaccid paralysis is a clinical manifestation characterized by weakness or paralysis and reduced muscle tone without other obvious cause .-Polio:...
that leaves its victim calm and conscious through the progression of symptoms. Death often occurs from respiratory failure
Respiratory failure
The term respiratory failure, in medicine, is used to describe inadequate gas exchange by the respiratory system, with the result that arterial oxygen and/or carbon dioxide levels cannot be maintained within their normal ranges. A drop in blood oxygenation is known as hypoxemia; a rise in arterial...
.
Bungarotoxin
Bungarotoxin
α-Bungarotoxin is one of the components of the venom of the elapid snake Taiwanese banded krait . It binds irreversibly and competitively to the acetylcholine receptor found at the neuromuscular junction, causing paralysis, respiratory failure and death in the victim...
is also a very potent neurotoxin. It binds irreversibly and competitively to the acetylcholine receptor found at the end plate of the neuromuscular junction, causing paralysis, and depending on the dose, can cause respiratory failure and death in the victim
Another very potent neurotoxin is taipoxin
Taipoxin
Taipoxin is an extremely potent neurotoxin developed by purifying the venom of the Australian taipan Oxyuranus microlepidotus. The toxin causes a gradual reduction to complete stop of evoked and spontaneous release of acetylcholine from motor nerve terminals. The victim dies from asphyxia caused by...
. The toxin causes a gradual reduction to complete stop of evoked and spontaneous release of acetylcholine from motor nerve terminals. If the dose is high enough, the victim can die from asphyxia caused by paralysis of the respiratory muscles.
Botulinum neurotoxins are the most potent natural toxins known(only tested on laboratory mice). They are produced by various toxigenic strains of Clostridium botulinum
Clostridium botulinum
Clostridium botulinum is a Gram-positive, rod-shaped bacterium that produces several toxins. The best known are its neurotoxins, subdivided in types A-G, that cause the flaccid muscular paralysis seen in botulism. It is also the main paralytic agent in botox. C. botulinum is an anaerobic...
and act as metalloproteinases that enter peripheral cholinergic nerve terminals and cleave proteins that are crucial components of the neuroexocytosis apparatus, causing a persistent but reversible inhibition of neurotransmitter release resulting in flaccid muscle paralysis.
Nerve agents
A number of artificial neurotoxins, known as nerve agentNerve agent
Nerve agents are a class of phosphorus-containing organic chemicals that disrupt the mechanism by which nerves transfer messages to organs...
s, have been developed for use as chemical weapons.
Neurotoxic drugs
Examples of neurotoxic drugs include, but are not limited to:- Certain psychostimulants, particularly methamphetamineMethamphetamineMethamphetamine is a psychostimulant of the phenethylamine and amphetamine class of psychoactive drugs...
and to a lesser degree dextroamphetamineDextroamphetamineDextroamphetamine is a psychostimulant drug which is known to produce increased wakefulness and focus as well as decreased fatigue and decreased appetite....
and amphetamineAmphetamineAmphetamine or amfetamine is a psychostimulant drug of the phenethylamine class which produces increased wakefulness and focus in association with decreased fatigue and appetite.Brand names of medications that contain, or metabolize into, amphetamine include Adderall, Dexedrine, Dextrostat,...
, when used at high doses have been shown to cause dopaminergicDopaminergicDopaminergic means related to the neurotransmitter dopamine. For example, certain proteins such as the dopamine transporter , vesicular monoamine transporter 2 , and dopamine receptors can be classified as dopaminergic, and neurons which synthesize or contain dopamine and synapses with dopamine...
and serotonergicSerotonergicSerotonergic or serotoninergic means "related to the neurotransmitter serotonin". A synapse is serotonergic if it uses serotonin as its neurotransmitter...
neurotoxicity via oxidative stressOxidative stressOxidative stress represents an imbalance between the production and manifestation of reactive oxygen species and a biological system's ability to readily detoxify the reactive intermediates or to repair the resulting damage...
. The neurotoxicity of stimulants such as cocaineCocaineCocaine is a crystalline tropane alkaloid that is obtained from the leaves of the coca plant. The name comes from "coca" in addition to the alkaloid suffix -ine, forming cocaine. It is a stimulant of the central nervous system, an appetite suppressant, and a topical anesthetic...
and methylphenidateMethylphenidateMethylphenidate is a psychostimulant drug approved for treatment of attention-deficit hyperactivity disorder, postural orthostatic tachycardia syndrome and narcolepsy. It may also be prescribed for off-label use in treatment-resistant cases of lethargy, depression, neural insult and obesity...
is debatable. - Empathogen-entactogensEmpathogen-entactogenThe terms empathogen and entactogen are used to describe a class of psychoactive drugs that produce distinctive emotional and social effects similar to those of MDMA. Putative members of this class include 2C-B, 2C-I, MDMA, MDA, MDEA, MBDB, 2C-T-7, and 2C-T-2, among others...
such as MDMA and MDAMDA-Companies, organizations and government bodies:* Maritime Domain Awareness, part of a U.S. Government interagency and international maritime security effort* MDA , formerly the Museum Documentation Association...
(except MDAI) have been found to cause neurotoxicity to serotonergicSerotonergicSerotonergic or serotoninergic means "related to the neurotransmitter serotonin". A synapse is serotonergic if it uses serotonin as its neurotransmitter...
nerve terminals, though this claim has been readily disputed. - L-DOPA induces damage to striatal dopamine neurons, particularly after chronic usage. Also shown to potentiate neurotoxicity of amphetamineAmphetamineAmphetamine or amfetamine is a psychostimulant drug of the phenethylamine class which produces increased wakefulness and focus in association with decreased fatigue and appetite.Brand names of medications that contain, or metabolize into, amphetamine include Adderall, Dexedrine, Dextrostat,...
s and other dopamine releasing agentReleasing agentA releasing agent , or simply releaser, is a drug that induces the release of a neurotransmitter from the presynaptic neuron into the synapse, leading to an increase in the extracellular concentrations of the neurotransmitter. Many drugs use neurotransmitter release to exert their psychological and...
s - NMDA receptor antagonistNMDA receptor antagonistNMDA receptor antagonists are a class of anesthetics that work to antagonize, or inhibit the action of, the N-methyl d-aspartate receptor . They are used as anesthesia for animals and, less commonly, for humans; the state of anesthesia they induce is referred to as dissociative anesthesia...
s like ketamineKetamineKetamine is a drug used in human and veterinary medicine. Its hydrochloride salt is sold as Ketanest, Ketaset, and Ketalar. Pharmacologically, ketamine is classified as an NMDA receptor antagonist...
, PCPPhencyclidinePhencyclidine , commonly initialized as PCP and known colloquially as angel dust, is a recreational dissociative drug...
, DXMDextromethorphanDextromethorphan is an antitussive drug. It is one of the active ingredients in many over-the-counter cold and cough medicines, such as Robitussin, NyQuil, Dimetapp, Vicks, Coricidin, Delsym, and others, including generic labels. Dextromethorphan has also found other uses in medicine, ranging...
, and dizocilpineDizocilpineDizocilpine , also known as MK-801, is a non-competitive antagonist of the N-methyl-d-aspartate receptor, a glutamate receptor. Glutamate is the brain's primary excitatory neurotransmitter...
(MK-801) have been shown to produce Olney's lesionsOlney's lesionsOlney's lesions, also known as NMDA receptor antagonist neurotoxicity , are a potential form of brain damage. They are named after John Olney, who conducted a study investigating neurotoxicity caused by PCP and related drugs in 1989.-History:...
in rodents, though this has never been observed in humans. - GHB receptorGHB receptorGamma-hydroxybutyrate receptor or GHB receptor , originally identified as GPR172A, is a G protein-coupled receptor that binds gamma-Hydroxybutyric acid .-History:...
agonists like GHB, GBLGamma-Butyrolactonegamma-Butyrolactone is a hygroscopic colorless oily liquid with a weak characteristic odor and is soluble in water. GBL is a common solvent and reagent in chemistry and is used as an aroma compound, as a stain remover, as a superglue remover, as a paint stripper, and as a solvent in some wet...
, and 1,4-BD1,4-Butanediol1,4-Butanediol is the organic compound with the formula HOCH2CH2CH2CH2OH. This colorless viscous liquid is derived from butane by placement of alcohol groups at each end of the chain. It is one of four stable isomers of butanediol.-Synthesis:...
, which damage the cerebralCerebral cortexThe cerebral cortex is a sheet of neural tissue that is outermost to the cerebrum of the mammalian brain. It plays a key role in memory, attention, perceptual awareness, thought, language, and consciousness. It is constituted of up to six horizontal layers, each of which has a different...
/prefrontal cortexPrefrontal cortexThe prefrontal cortex is the anterior part of the frontal lobes of the brain, lying in front of the motor and premotor areas.This brain region has been implicated in planning complex cognitive behaviors, personality expression, decision making and moderating correct social behavior...
and hippocampusHippocampusThe hippocampus is a major component of the brains of humans and other vertebrates. It belongs to the limbic system and plays important roles in the consolidation of information from short-term memory to long-term memory and spatial navigation. Humans and other mammals have two hippocampi, one in...
via oxidative stressOxidative stressOxidative stress represents an imbalance between the production and manifestation of reactive oxygen species and a biological system's ability to readily detoxify the reactive intermediates or to repair the resulting damage...
. - NMDA receptorNMDA receptorThe NMDA receptor , a glutamate receptor, is the predominant molecular device for controlling synaptic plasticity and memory function....
agonists like ibotenic acidIbotenic acidIbotenic acid is a chemical compound that is naturally occurring in the mushrooms Amanita muscaria and Amanita pantherina, among others...
(which is found in Amanita muscariaAmanita muscariaAmanita muscaria, commonly known as the fly agaric or fly amanita , is a poisonous and psychoactive basidiomycete fungus, one of many in the genus Amanita...
mushrooms) and GABA receptorGABA receptorThe GABA receptors are a class of receptors that respond to the neurotransmitter gamma-aminobutyric acid , the chief inhibitory neurotransmitter in the vertebrate central nervous system...
antagonists like picrotoxinPicrotoxinPicrotoxin, also known as cocculin, is a poisonous crystalline plant compound, first isolated by Pierre Boullay in 1812. The name "picrotoxin" is a combination of the Greek words "picros" and "toxicon" ....
, and bicucullineBicucullineBicuculline is a light-sensitive competitive antagonist of GABAA receptors. It was originally identified in 1932 in plant alkaloid extracts and has been isolated from Dicentra cucullaria, Adlumia fungosa, Fumariaceae, and several Corydalis species. Since it blocks the inhibitory action of GABA...
are neurotoxic via excitotoxicity. - Several antipsychoticAntipsychoticAn antipsychotic is a tranquilizing psychiatric medication primarily used to manage psychosis , particularly in schizophrenia and bipolar disorder. A first generation of antipsychotics, known as typical antipsychotics, was discovered in the 1950s...
s have been linked to brain gray/white matter loss. - Others such as 5,7-DHT5,7-Dihydroxytryptamine5,7-Dihydroxytryptamine is a neurotoxin used to selectively kill serotonergic neurons in scientific research, in the same way that 6-hydroxydopamine is used to kill dopaminergic cells.- See also :* 6-Hydroxydopamine...
, 6-OHDA, MPP+MPP+MPP+ is a positively charged molecule with chemical formula C12H12N+. It is toxic and acts by interfering with oxidative phosphorylation in mitochondria, causing depletion of ATP and cell death...
, MPTPMPTPMPTP is a neurotoxin precursor to MPP+, which causes permanent symptoms of Parkinson's disease by destroying dopaminergic neurons in the substantia nigra of the brain...
, PBAPara-Bromoamphetaminepara-Bromoamphetamine , also known as 4-bromoamphetamine , is an amphetamine derivative which acts as a serotonin-norepinephrine-dopamine releasing agent and produces stimulant effects...
, PCAPara-Chloroamphetaminepara-Chloroamphetamine , also known as 4-chloroamphetamine , is an amphetamine derivative and monoamine releaser similar to MDMA, but with substantially higher neurotoxicity, thought to be due to the unrestrained release of both serotonin and dopamine as with MDMA itself...
, and PIAPara-Iodoamphetaminepara-Iodoamphetamine , also known as 4-iodoamphetamine , is a research chemical of the phenethylamine and amphetamine chemical classes.It acts as a selective serotonin releasing agent and is also a MAOI....
.
See also
- NeurotoxicityNeurotoxicityNeurotoxicity occurs when the exposure to natural or artificial toxic substances, which are called neurotoxins, alters the normal activity of the nervous system in such a way as to cause damage to nervous tissue. This can eventually disrupt or even kill neurons, key cells that transmit and process...
- Olney's LesionsOlney's lesionsOlney's lesions, also known as NMDA receptor antagonist neurotoxicity , are a potential form of brain damage. They are named after John Olney, who conducted a study investigating neurotoxicity caused by PCP and related drugs in 1989.-History:...
- ToxinToxinA toxin is a poisonous substance produced within living cells or organisms; man-made substances created by artificial processes are thus excluded...
- Microbial toxinsMicrobial toxinsMicrobial toxins are toxins produced by microorganisms, including bacteria, viruses and fungi. Microbial toxins are important virulence determinants responsible for microbial pathogenicity and/or evasion of the host immune response. Some bacterial toxins, such as Botulinum neurotoxins, are the most...
- Sea anemone neurotoxinSea anemone neurotoxinSea anemone neurotoxin is the name given to neurotoxins produced by sea anemones with related structure and function.A number of proteins belonging to this family, including calitoxin and anthopleurin...
- Snake toxins
- BmKAEPBmKAEPBmKAEP is a neurotoxin from the venom of the Manchurian scorpion . It is a β-toxin, which shift the activation voltage of sodium channels towards more negative potentials.- Etymology :...