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Title: What is the difference between a neurotransmitter and a neuromodulator? Post by: Smilez on May 9, 2013 are they the same?
Title: What is the difference between a neurotransmitter and a neuromodulator? Post by: leemons on May 9, 2013 neural transmitter: chemical substance released
in minute amounts by the ending of a nerve fibre Title: What is the difference between a neurotransmitter and a neuromodulator? Post by: Leen on May 9, 2013 A neurotransmitter is one of several substances released by the nerve ending of a neuron that is used to communicate with the adjacent neuron. Chemicals like Serotonin, Acetylcholine, Dopamine, GABA, Glycine, and Norepinephrine are considered neurotransmitters. They are released by the presynaptic neuron and either excite or inhibit the post synaptic neuron. They are quickly degraded in the synaptic cleft or taken up by the presynaptic neuron to limit the amount of time they are in the synaptic cleft.
Neuromodulators are not the same. They are released by the nerve endings and have their effect sometimes quite far from the neuron from which they were released. They are not rapidly degraded or taken up, so the amount of time for their activity is not limited as in neurotransmitters. They can either dampen or enhance the excitability of their effector neurons. Examples of neuromodulators are opioid peptides such as enkephalins, endorphins, dynorphins. Some neurotransmitters also act as neuromodulators: substance P, octopamine, serotonin, an acetylcholine are such examples. |