Genetic labeling of both the axons of transduced, glutamatergic neurons in rat postrhinal cortex and their postsynaptic neurons in other neocortical areas by Herpes Simplex Virus vectors that coexpress an axon-targeted β-galactosidase and wheat germ aggl

►Expressing genetic tracers in neocortical neurons can map neocortical circuits. ►Axon-targeted β-gal maps commissural and associative projections of neocortex neurons. ►Wheat germ agglutinin (WGA) identifies postsynaptic neurons for transduced neurons. ►Coexpressing WGA and the β-gal maps projections and identifies postsynaptic neurons.