In chronic toxoplasmosis infection (ME-49 strain), (1) the cyst stage showed higher prevalence in the hippocampus and the amygdala when compared with other brain areas, (2) establishment of chronic toxoplasmosis occurs under the umbrella of TNF-α/NF-κβ, (3) TNF-α and NF-κβ are positively correlated, and (4) cerebral cells were deprived of IGF-1R expression along with this parasitic infection. This evidence concerns the gene TNF and cyst.