Allergic rhinitis in BALB/c mice is associated with behavioral and hippocampus changes and neuroinflammation via the TLR4/ NF-κB signaling pathway

Allergic rhinitis is a systemic disease with high prevalence, which some of its neuropsychological problems have been reported. The primary pathophysiology and mechanism of the neuropsychological dysfunction of AR patients have not been described yet, so here we subjected an animal model of AR to identify any behavioral or seizure threshold changes and to assess the pathophysiology of the disease.Eighty male BALB/C mice were randomly divided into the allergic rhinitis group and controls. Allergic rhinitis was induced in the first group by administering OVA and aluminum hydroxide intraperitoneally and then nasal injection of OVA for 14 consecutive days. Both groups were subjected to different tests for assessing depressive-like behavior, anxiety, spatial and contextual memory, and learning and seizure threshold. Hippocampus and plasma samples of mice were subjected for analyzing cytokines and immune modulators and for pathology and immunohistochemistry evaluation.The depressive and anxiety-like behavior were increased in AR, and the spatial learning and memory were disturbed in the AR group. Also, AR mice had lower seizure thresholds compared to controls. Lab data suggested that TLR4, NF-κB, IL-1β, and TNFα expressions were increased in the AR hippocampus as well as their plasma proinflammatory cytokines. Likewise, demyelination, cell death, and M1 macrophage aggregation were increased in the AR hippocampus.Behavioral and cognitive problems should be taken seriously in patients with AR or other atopic diseases, and more investigating is required to clear the pathophysiology behind it and its treatment.