This assay technique was able to show that the number of spinal and vagal sensory afferents projecting in the pancreas is lower in female mice as compared to age-matched males. Pseudorabies virus (PRV)-Bartha encoding green fluorescent protein and red fluorescent protein are injected into mouse pancreas or liver (control). Mice are sacrificed five days after infection. Dorsal root and nodose ganglia can be collected, fixed, sliced, and imaged for endogenous GFP and RFP.