Is It a Homunculus?

In repeated informations in the peritonium, they activate different subsets of cells within the insular cortex. Maybe I'm missing this, but the mouse they're using is a C-poss. It's a trap mouse. And so I don't know how they can restrict the expression or that trapping to theinsular cortex. They use a viral vector that expresses the fast trap only in the right insular cortex and it gets there. But this is where I'm like, did they show that? Did they show like the virus really just hitting the insular and how many cells they got?