As parvalbumin-expressing interneurons represent a very important subpopulation of hippocampal interneurons (amounting to about 40%), are functionally very important and are the most vulnerable in various neurological disorders [22,23], we examined this subpopulation of inhibitory interneurons in AAV-L1 and AAV-GFP-treated mice, as well as wild-type control mice. The gene discussed is PVALB; the disease is nervous system disorder.