CHAT and schizophrenia: To gain insight into the mechanisms underlying behavioral deficits, we first measured the protein expression levels of ChAT responsible for the synthesis of acetylcholine (Ach) and found that it was downregulated in the BF and PFC (one of the main targets for projections of BF cholinergic neurons and that is closely linked to schizophrenia), but not in the CPu nor PM areas (Fig. 3a and Supplementary Fig. 2b, f) in ChAT-Cre;Hrh1fl/fl mice.