Editing Neurotransmitter (section)

==Identification==
To identify neurotransmitters, the following criteria are typically considered:
# Synthesis: The chemical must be produced within the neuron or be present in it as a precursor molecule.
# Release and response: When the neuron is activated, the chemical must be released and elicit a response in target cells or neurons.
# Experimental response: Application of the chemical directly to the target cells should produce the same response observed when the chemical is naturally released from neurons.
# Removal mechanism: There must be a mechanism in place to remove the neurotransmitter from its site of action once its signaling role is complete.<ref>{{Cite journal |last1=Teleanu |first1=Raluca Ioana |last2=Niculescu |first2=Adelina-Gabriela |last3=Roza |first3=Eugenia |last4=Vladâcenco |first4=Oana |last5=Grumezescu |first5=Alexandru Mihai |last6=Teleanu |first6=Daniel Mihai |date=2022-05-25 |title=Neurotransmitters—Key Factors in Neurological and Neurodegenerative Disorders of the Central Nervous System |journal=International Journal of Molecular Sciences |language=en |volume=23 |issue=11 |pages=5954 |doi=10.3390/ijms23115954 |issn=1422-0067 |pmc=9180936 |pmid=35682631 |doi-access=free }}</ref>

However, given advances in [[pharmacology]], [[genetics]], and chemical [[neuroanatomy]], the term "neurotransmitter" can be applied to chemicals that:
* Carry messages between neurons via influence on the postsynaptic membrane.
* Have little or no effect on membrane voltage, but have a common carrying function such as changing the structure of the synapse.
* Communicate by sending reverse-direction messages that affect the release or [[reuptake]] of transmitters.

The anatomical localization of neurotransmitters is typically determined using [[Immunocytochemistry|immunocytochemical]] techniques, which identify the location of either the transmitter substances themselves or of the enzymes that are involved in their synthesis. Immunocytochemical techniques have also revealed that many transmitters, particularly the [[neuropeptide]]s, are co-localized, that is, a neuron may release more than one transmitter from its [[synaptic terminal]].<ref name="BioPsych Breedlove & Watson">{{cite book| vauthors = Breedlove SM, Watson NV |author1-link=Marc Breedlove|title=Biological psychology : an introduction to behavioral, cognitive, and clinical neuroscience|date=2013|publisher=Sinauer Associates|location=Sunderland, MA|isbn=978-0878939275|edition=Seventh}}</ref> Various techniques and experiments such as [[staining]], stimulating, and collecting can be used to identify neurotransmitters throughout the [[central nervous system]].<ref name="Kolb Intro to Brain & Behavior">{{cite book| vauthors = Whishaw B, Kolb IQ |title=An introduction to brain and behavior|date=2014|publisher=Worth Publishers|location=New York, NY|isbn=978-1429242288|pages=150–151|edition=4th}}</ref>