Specifically, periodontitis related specific cytokines i.e. IL-6, IL-1, Tumor necrosis factor alpha (TNF-α), C-reactive protein (CRP), and alpha1-antichymotrypsin, neuropeptides such as insulin-like growth factor-2 (IGF-2), neuropeptide Y, substance P, neurokinin A, calcitonin gene-related peptide (CGRP), and vasoactive intestinal polypeptide (VIP), and a polybacterial pathogenic consortium of porphyromonas gingivalis, tannerella forsythia, and treponema denticola, were involved in the mediation and exacerbation of the associated neuronal cognitive pathologies. This evidence concerns the gene TNF and periodontitis.