In particular, dysfunction of fast spiking, parvalbumin-expressing interneurons (PV-INs) are implicated in epilepsy, neurodevelopmental, and neurodegenerative diseases including Alzheimer’s disease (AD)13,14, a likely consequence of their role in maintaining circuit excitability locally, and brain state more generally, coupled with their substantial energy requirements15. This evidence concerns the gene PVALB and early-onset autosomal dominant Alzheimer disease.