CHRNA7 and schizophrenia: Elevated KYNA synthesis in schizophrenia brains [21,52], typically a function of Th2 response (Figure 1), can inhibit NR1 subunit of NMDAR and alpha 7 nicotinic acetylcholine receptor (α7nAchR) [195], leading to decreased NMDAR function and reduced α7nAchR-mediated glutamate release [195].