Advances in spatial mass spectrometry enable in-depth neuropharmacodynamics.

Mass spectrometry imaging (MSI) is a powerful technique that combines the ability of microscopy to provide spatial information about multiple molecular species with the specificity of mass spectrometry (MS) for unlabeled mapping of analytes in diverse biological tissues. Initial pharmacological applications focused on drug distributions in different organs, including the compartmentalized brain. However, recent technological advances in instrumentation, software, and chemical tools have allowed its use in quantitative spatial omics. It now enables visualization of distributions of diverse molecules at high lateral resolution in studies of the pharmacokinetic and neuropharmacodynamic effects of drugs on functional biomolecules. Therefore, it has become a versatile technique with a multitude of applications that have transformed neuropharmacological research and enabled research into brain physiology at unprecedented resolution, as described in this review.