The effect of Toxoplasmosis disease on plasma serotonin concentration in Sheep

Toxoplasma gondii is a protozoan parasite able to alter intermediate host behavior. Various studies support the correlation between latent toxoplasmosis and neuropsychiatric disorders in both animals and humans. An alteration in neurotransmission has been suggested as one of the factors influencing these mood disorders. Most of the studies is focused on mice, without considering other species. Since animal findings might be traced to human species, a better comprehension of these processes in other species might be beneficial not only for veterinary but also for human medicine. The aim of this research was to assess the variation of plasma serotonin concentration among infected and uninfected sheep (control group). Higher serotonin levels in infected animals compared to controls were observed, suggesting an influence of T. gondii infection on serotoninergic metabolism. No significant variation in hematological parameters between the two groups was observed. These data are coherent to a status of latent disease in infected sheep.