Netrin-G1 and netrin-G2, belonging to a vertebrate-specific subfamily of the netrin family, distribute on axons of distinct neuronal pathways. To add to the array of molecular probes available for labeling unique neuronal circuits, we generated monoclonal antibodies against the netrin-G1 and netrin-G2 proteins. The monoclonal antibody clones 171A18 and 30B15 differentially labeled specific neuronal circuits, the so-called netrin-G1 or netrin-G2 circuits in mice, respectively. Epitope mapping revealed linear epitopes for these monoclonal antibodies, which are common among splicing variants, and suggested that the anti-netrin-G1 monoclonal antibodies are applicable to various species including humans.