The lack of significant changes in the expression of ahr, gpr35 genes and katI, katII and kmo enzymes in the hippocampus after short-term exposure to scopolamine indicates that the molecular mechanisms responsible for reversible cognitive deficits induced by blockade of muscarinic receptors are not associated with the activation of the KP, which is involved in chronic neurodegenerative and inflammatory processes. The gene discussed is KMO; the disease is Cognitive impairment.