TNF and periodontitis: They reported that the animals submitted to both pathological stimuli presented the highest expression of pro-inflammatory mediators [TNF-α, IL-1β and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB)] in the frontal cortex, dysregulation of the HPA stress axis, presence of F. nucleatum in the brain parenchyma and increased periodontal clinical variables such as alveolar bone levels, when compared with the control group without periodontitis or CMS.