INS and cognitive disorder: PQ induces primaryhippocampal neuron cell death through an increase of Aβ andp-tau levels.6 PQ induces substantia nigraneuronal loss through INF-γ silencing.8 INF-γ long-term treatment induces hippocampal neurodegenerationand cognitive decline in mice,9 and PQtreatment of IFN-γ knockout mice reverted the substantia nigraneuronal loss induced after PQ treatment alone.8 Insulin signaling pathway disruption induces hippocampalneuronal loss and produces cognitive disorders, and insulin treatmentreverts these effects.10,28,29 All these previous studies support our results.