Experimental design for cell type-specific trans-synaptic tracing using PRV-Introvert-GFP, a modified conditional alpha-Herpes Bartha virus, in SST-Cre mice.

A) Cre-dependent Introvert sequence used for cell type-specific tracing. B) Experimental timeline for determination of monosynaptic time point. We collected tissue from 2 mice every 12 hr and observed GFP expression in known NAc afferents. By collecting sections at serial time points, we determined time points at which viral labeling is first present in known NAc afferents. PFC–Prefrontal cortex, AMY–amygdala, HYP–hypothalamus, VTA–ventral tegmental area. These four regions shown as examples of a larger number of known input regions (see Fig 2).