SST and early-onset autosomal dominant Alzheimer disease: Also, parvalbumin-positive (PV) and somatostatin-positive (SST) interneurons, the two major subtypes of hippocampal interneurons [30] that are critically involved in oscillogenesis [24, 25, 31], are reported to be impaired in mouse models of Alzheimer’s disease [5–8, 27, 32, 33].