CHRNA4 and schizophrenia: Recent studies in humans have underscored the potential importance of nAChRs in the pathophysiology of schizophrenia owing to: (1) the abnormal expression of nAChRs in post-mortem brains of schizophrenic patients; (2) the striking association between smoking (a nicotine delivery system) and schizophrenia; (3) the improved cognition seen in animals and humans with nicotine exposure; (4) the genetic association between the human α7-nAChR and schizophrenia; and (5) the potential efficacy of nAChR agonists as treatments for schizophrenia [15]–[17].