neurotransmitter

neurotransmitter
/noor'oh trans"mit euhr, -tranz"-, nyoor'-/, n.
any of several chemical substances, as epinephrine or acetylcholine, that transmit nerve impulses across a synapse to a postsynaptic element, as another nerve, muscle, or gland.
[1960-65; NEURO- + TRANSMITTER]

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Chemical released by neurons to stimulate neighbouring neurons, allowing impulses to be passed from one cell to the next throughout the nervous system.

A nerve impulse arriving at the axon terminal of one neuron stimulates release of a neurotransmitter, which crosses the microscopic gap (see synapse) in milliseconds to the adjoining neuron's dendrite. Many chemicals are believed to act as neurotransmitters. The few that have been identified include acetylcholine, dopamine, and serotonin. Some neurotransmitters activate neurons; others inhibit them. Some mind-altering drugs act by changing synaptic activity.

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also called  chemical transmitter , or  transmitter substance 

      any of a group of chemical agents released by neurons (neuron) (nerve cells) to stimulate neighbouring neurons, thus allowing impulses to be passed from one cell to the next throughout the nervous system.

      The site where neurons meet is called the synapse and consists of the axon terminal (transmitting end) of one cell and the dendrite (receiving end) of the next. A microscopic gap called a synaptic cleft exists between the neurons. When a nerve impulse arrives at the axon terminal of one neuron, a chemical substance is released through the presynaptic membrane, traveling in milliseconds across the synaptic cleft to the postsynaptic membrane of the adjoining neuron. The chemical release is stimulated by the electrical activity of the neuron.

      Although a large number of chemical substances are believed to act as neurotransmitters, only a few have been identified. Among those known are acetylcholine, norepinephrine (noradrenalin), dopamine, and serotonin. Some chemical agents, such as acetylcholine, activate neurons, while others act as inhibiting substances.

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Universalium. 2010.

Look at other dictionaries:

  • Neurotransmitter — sind endogene, biochemische Botenstoffe, welche die Information von einer Nervenzelle zur anderen über die Kontaktstelle der Nervenzellen, der Synapse, weitergeben. In die Synapse einlaufende elektrische Impulse (Aktionspotentiale) veranlassen… …   Deutsch Wikipedia

  • Neurotransmitter — ⇒ Transmitter …   Deutsch wörterbuch der biologie

  • neurotransmitter — (n.) 1961, from NEURO (Cf. neuro ) + TRANSMITTER (Cf. transmitter) …   Etymology dictionary

  • neurotransmitter — ► NOUN Physiology ▪ a chemical substance released from a nerve fibre and bringing about the transfer of an impulse to another nerve, muscle, etc. DERIVATIVES neurotransmission noun …   English terms dictionary

  • neurotransmitter — [noor΄ō trans′mit΄ər, nyoor΄ō trans′mit΄ər; noor΄ō tranz′mit΄ər, nyoor΄ōtranz′mit΄ər] n. a biochemical substance, as acetylcholine or norepinephrine, that transmits or inhibits nerve impulses at a synapse …   English World dictionary

  • Neurotransmitter — For an introduction to concepts and terminology used in this article, see Chemical synapse. Structure of a typical chemical synapse Postsynaptic density Voltage gated Ca++ c …   Wikipedia

  • Neurotransmitter — nervale Überträgerstoffe * * * Neu|ro|trans|mit|ter 〈m. 3; Med.〉 Substanz, die an den Synapsen die Erregungsübertragung bewerkstelligt; Sy Transmitter (2) [<grch. neuron „Nerv“ + lat. transmittere „hinüberschicken“] * * * Neu|ro|trans|mịt|ter …   Universal-Lexikon

  • Neurotransmitter —    Neurotransmitters are the chemicals involved in communication between nerve cells ( neurons ). Substances released from the end bulb of an upstream ( presynaptic ) neuron into the synaptic space in order to excite or inhibit the downstream (… …   Historical dictionary of Psychiatry

  • Neurotransmitter — A chemical that is released from a nerve cell which thereby transmits an impulse from a nerve cell to another nerve, muscle, organ, or other tissue. A neurotransmitter is a messenger of neurologic information from one cell to another. * * * Any… …   Medical dictionary

  • neurotransmitter — n. a chemical substance released from nerve endings to transmit impulses across synapses to other nerves and across the minute gaps between the nerves and the muscles or glands that they supply. Outside the central nervous system the chief… …   The new mediacal dictionary

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