Functional Neuron Markers (FNMs)

Functional Neuron Markers (FNMs) are a class of molecular markers specifically expressed in different functional subtypes of neurons, which are directly associated with the core physiological functions, signal transduction, and phenotypic characteristics of neurons. They mainly include enzymes, neurotransmitter receptors, transporters, and neuropeptides, serving as core tools in biological research for analyzing the structure and function of the nervous system and revealing the pathogenesis of neurological diseases. Unlike general markers such as NeuN and MAP2 that only identify the morphology or maturation status of neurons, the core characteristic of FNMs lies in "functional relevance" — their expression abundance, cellular localization, and modification status are highly coupled with the specific functions of neurons (e.g., neurotransmitter synthesis and release, excitation-inhibition regulation, sensory and motor signal transmission), which enables accurate distinction of neuronal functional subtypes and provides a molecular ruler for refined research on the nervous system.