Here, we showed that miR-26a-3p deficiency within hippocampal regions leads to the activation of microglia, increased level of pro-inflammatory cytokines and behavioral disorders in rats, effects which appear to be mediated by directly targeting the p38 mitogen-activated protein kinase (MAPK)–NF-κB signaling pathway. The gene discussed is NFKB1; the disease is Atypical behavior.