Figure 1: Schematic overview of the application of chemical biology strategies in neuroscience to explore neurochemical protein modification and epigenetics. Neurons (top left) produce a variety of neurochemical compounds, including monoamines that serve as neurotransmitters (grey circles). Monoamines, such as dopamine, epinephrine, melatonin and serotonin, can be chemically modified with various functional groups (top right). If monoamines form covalent bonds with proteins or DNA-histone complexes, the application of monoamine analogues (red stars) enables detection and visualization of this modification. For instance, attaching a reporter molecule to the monoamine analogue via copper(I)-catalyzed azide-alkyne cycloaddition allows interrogation of biological substrates (not shown).