ABSTRACT The previous study elucidated that the C‐reactive protein (CRP)/bone morphogenetic protein 4 (BMP4) signaling pathway mediates periodontitis‐associated anxiety‐like behaviors in rats. This molecular crosstalk along the periodontal‐hippocampal axis provides novel insights into the etiology and mechanisms of emotional disorders. However, several key issues remain to be further discussed regarding the establishment of the core finding linking peripheral inflammation to emotional disorders