5-Hydroxytryptamine, Glutamate, and ATP: Much More Than Neurotransmitters

Abstract

5-hydroxytryptamine (5-HT) is derived from the essential amino acid L-tryptophan. Although the compound has been studied extensively for its neuronal handling and synaptic actions, serotonin 5-HT receptors can be found extra-synaptically and not only in neurons but in many types of mammalian cells, inside and outside the central nervous system (CNS). In sharp contrast, glutamate (Glu) and ATP are better known as metabolism-related molecules, but they also are neurotransmitters, and their receptors are expressed on almost any type of cell inside and outside the nervous system. Whereas 5-hydroxytryptamine and Glu are key regulators of the immune system, ATP actions are more general. 5-hydroxytryptamine, ATP and Glu act through both G protein-coupled receptors (GPCRs), and ionotropic receptors, i.e., ligand gated ion channels. These are the three examples of neurotransmitters whose actions as holistic regulatory molecules are briefly put into perspective here.

UHPLC-MS/MS combined with microdialysis for simultaneous determination of nicotine and neurotransmitter metabolites in the rat hippocampal brain region: application to pharmacokinetic and pharmacodynamic study

“…5-HT is a crucial monoamine neurotransmitter, with its dysregulation potentially closely linked to neurological disorders, including Alzheimer's disease, and playing a significant role in regulating human emotions. 41 Increased levels of 5-HT reduce impulsivity and produce a calming effect. 42 With the concentration of nicotine metabolites increasing, the concentrations of 5-HT and its metabolite 5-HIAA also increase (Fig.…”

Excessive level of dietary insect protein negatively changed growth metabolomic and transcriptomic profiles of largemouth bass (Micropterus salmoides)

“…The decrease of 5-HTP and increase of L -Trp in the liver of the HI40 fish indicate that the efficiency of 5-HT generation may be reduced. Furthermore, 5-HT is a regulator of the immune system ( Franco et al., 2021 ). This is consistent with the findings that the downregulated genes are enriched in immune-related pathways.…”

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