neurotransmitter


Also found in: Dictionary, Thesaurus, Medical, Wikipedia.
Related to neurotransmitter: serotonin, dopamine

neurotransmitter,

chemical that transmits information across the junction (synapsesynapse
, junction between various signal-transmitter cells, either between two neurons or between a neuron and a muscle or gland. A nerve impulse reaches the synapse through the axon, or transmitting end, of a nerve cell, or neuron.
..... Click the link for more information.
) that separates one nerve cell (neuron) from another nerve cell or a muscle. Neurotransmitters are stored in the nerve cell's bulbous end (axon). When an electrical impulse traveling along the nerve reaches the axon, the neurotransmitter is released and travels across the synapse, either prompting or inhibiting continued electrical impulses along the nerve. There are more than 300 known neurotransmitters, including chemicals such as acetylcholineacetylcholine
, a small organic molecule liberated at nerve endings as a neurotransmitter. It is particularly important in the stimulation of muscle tissue. The transmission of an impulse to the end of the nerve causes it to release neurotransmitter molecules onto the surface of
..... Click the link for more information.
, norepinephrinenorepinephrine
, a neurotransmitter in the catecholamine family that mediates chemical communication in the sympathetic nervous system, a branch of the autonomic nervous system.
..... Click the link for more information.
, adenosine triphosphateadenosine triphosphate
(ATP) , organic compound composed of adenine, the sugar ribose, and three phosphate groups. ATP serves as the major energy source within the cell to drive a number of biological processes such as photosynthesis, muscle contraction, and the synthesis of
..... Click the link for more information.
, and the endorphinsendorphins
, neurotransmitters found in the brain that have pain-relieving properties similar to morphine. There are three major types of endorphins: beta endorpins, found primarily in the pituitary gland; and enkephalins and dynorphin, both distributed throughout the nervous
..... Click the link for more information.
, and gases, such as nitric oxidenitric oxide
or nitrogen monoxide,
a colorless gas formed by the combustion of nitrogen and oxygen as given by the reaction: energy + N2 + O2 → 2NO; m.p. −163.6°C;; b.p. −151.8°C;.
..... Click the link for more information.
. Neurotransmitters transmit information within the brain and from the brain to all the parts of the body. Acetylcholine, for example, sends messages to the skeletal muscles, sweat glands, and heart; serotoninserotonin
, organic compound that was first recognized as a powerful vasoconstrictor occurring in blood serum. It was partially purified, crystallized, and named in 1948, and its structure was deduced a year later.
..... Click the link for more information.
 release underlies the process of learning and consciousness.

The actions of some drugs mimic those of naturally occurring neurotransmitters. The pain-regulating endorphins, for example, are similar in structure to heroin and codeine, which fill endorphin receptors to accomplish their effects. The wakefulness that follows caffeine consumption is the result of its blocking the effects of adenosine, a neurotransmitter that inhibits brain activity. Abnormalities in the production or functioning of certain neurotransmitters have been implicated in a number of diseases including Parkinson's diseaseParkinson's disease
or Parkinsonism,
degenerative brain disorder first described by the English surgeon James Parkinson in 1817. When there is no known cause, the disease usually appears after age 40 and is referred to as Parkinson's disease; a number of genes have
..... Click the link for more information.
, amyotrophic lateral sclerosisamyotrophic lateral sclerosis
(ALS) or motor neuron disease,
sometimes called Lou Gehrig's disease, degenerative disease that affects motor neurons in the brain and spinal cord, preventing them from sending impulses to the muscles.
..... Click the link for more information.
, and clinical depressiondepression,
in psychiatry, a symptom of mood disorder characterized by intense feelings of loss, sadness, hopelessness, failure, and rejection. The two major types of mood disorder are unipolar disorder, also called major depression, and bipolar disorder, whose sufferers are
..... Click the link for more information.
.

neurotransmitter

[‚nu̇r·ō‚tranz′mid·ər]
(neuroscience)
A chemical agent that is released by a neuron at a synapse, diffuses across the synapse, and acts upon a postsynaptic neuron, a muscle, or a gland cell.
References in periodicals archive ?
LE: Have you seen neurotransmitter testing work in clinical practice?
Neurotransmitter testing provides an instant replay.
Indeed, prior to the study, there were only two other systems in the brain where neurons had been observed to co-release excitatory and inhibitory neurotransmitters -- in a particular connection in the hippocampus and in the brainstem during development of the brain's auditory map.
Chen's team found that the GABA neurotransmitter was drastically increased in the deformed versions of the normally large, star-shaped "astrocyte" cells which, in a healthy individual, surround and support individual neurons in the brain.
To find out which neurons control the stem cells, the researchers inserted special light-activating proteins into the neurons that trigger the cells to send an electrical pulse, as well as to release neurotransmitter, when light shines on them.
By the 1950s researchers had shown that noradrenalin and adrenalin were neurotransmitters synthesized in the body and that they could stimulate two types of receptors which had been termed 'alpha' and 'beta.
They contain receptors for the neurotransmitter dopamine, which creates pleasurable feelings and craving when people first fall in love.
Factors such as the production of pathological tangles of tau protein fibers, abnormal levels of key neurotransmitters, and changes in immune response are also part of the overall picture we see in AD.
Adding specific amino acid supplements can alter urinary neurotransmitter values.
The artificial cell is made from an electricity-conducting plastic and can deliver different kinds of neurotransmitter.
Cholinergic: Related to the neurotransmitter acetylcholine.
Neurotransmitter diseases is an umbrella term for the myriad of disorders that play havoc with the array of substances (neurotransmitters) that are released at the junction of one neuron and expedite the expected reaction on another neuron that eventually commands, encourages, or leverages an organ to do its thing.