**6. Concluding remarks**

This chapter has introduced the utility of mass spectrometry imaging (MSI) for small molecules, with a specific focus on neurotransmitters (NTs). Methods that have resulted in enhanced signals of NTs were highlighted, with alternative matrix materials and chemical derivatization of analytes the two main points of discussion. Future research is needed in both of these areas to determine optimum conditions and applications, as well as establishing standard procedures so that broad application of MSI can continue. Finally, an area not discussed here that is relevant to these

**109**

*Mass Spectrometry Imaging of Neurotransmitters DOI: http://dx.doi.org/10.5772/intechopen.93835*

The author declares no conflict of interest.

DESI desorption electrospray ionization

CHCA α-cyano-4-hydroxy cinnamic acid

LC-MS liquid chromatography mass spectrometry MALDI matrix-assisted laser desorption ionization

qMSI quantitative mass spectrometry imaging NEDC N-(1-napthyl)ethylenediamine dihydrochloride

nation of small molecules.

**Acknowledgements**

**Conflict of interest**

**Nomenclature**

DAG diacylglycerol

DAN 1,5-diaminonapthalene

Glucose 6-P glαucose 6-phosphate HTP high throughput ITO indium tin oxide

DHB 2,5-dihydroxybenzoic acid DPP 2,4-diphenyl pyranylium

LATT laser-assisted tissue transfer

MSI mass spectrometry imaging

PCA principal component analysis

PE phospatidylethanolamine PEP phosphoenolpyruvic acid PG phosphatidylglycerol PI phosphatidylinositol PC phosphatidylcholine SA sinapic (or sinapinic) acid

THAP trihydroxyacetophenone

NT neurotransmitter NP nanoparticle PA phosphatidic acid

PChol phosphocholine

TAG triacylglycerol

techniques and that will likely be explored in the future is the quantitative determi-

KS thanks the University of Scranton and the Chemistry Department for providing facilities, equipment, and financial support for any referenced experiments. KS thanks the Johns Hopkins Applied Imaging Mass Spectrometry (AIMS) Core Facility at the Johns Hopkins University School of Medicine for undertaking the imaging experiments referenced in this chapter. Lastly, KS thanks Nolan

McLaughlin and Tyler Bielinski for tagging along for the science journey.

techniques and that will likely be explored in the future is the quantitative determination of small molecules.
