INFLUENCE OF DEFICIENCY OF TUMOR NECROSIS FACTOR ON BEHAVIOR AND BRAIN DOPAMINE SYSTEM IN MICE
The tumor necrosis factor (TNF) is an important modulator of central nervous system function. In this paper, the effect of deficiency of the tumor necrosis factor on locomotor activity, anxiety and the state of the brain dopamine system in mice was studied. Males of C57Bl/6 (wild type) and C57BL/6-Tnf-/- (TNF KO, with tumor necrosis factor knockout, derived from the C57Bl/6 genome) mouse strains, were used. In the open field test, mice of these strains did not differ in the length of the travelled path, but TNF KO mice spent more time in the center of the arena and showed a higher level of rearings, that indicates a decreased level of anxiety in these animals compared to the wild type. In addition, TNF KO mice demonstrated the augmentation of mRNA level of the gene encoding the dopamine D2 receptor and the reduction of the dopamine level in the substance nigra, as well as the decrease in mRNA level of the gene encoding the dopamine D1 receptor in the hippocampus. The results indicate the effect of knockout of the tumor necrosis factor on anxiety behavior and the dopamine system of the brain in mice.