We have assessed TNF(-/-), TNF-R1(-/-) and TNF-R2(-/-) mice against C57BL/6 wild-type (WT) mice from 12 weeks of age in order to evaluate measures of spatial memory and learning in the Barnes maze (BM) and Y-maze, as well as other behaviours such as exploration, social interaction, anxiety and depression-like behaviour in a battery of tests.
The depression-like behavior was virtually abolished in TNFα p55 receptor-knockout mice, and increased B1 receptor mRNA expression was completely absent in this mouse strain.
Circulating levels of interleukin-6 (IL-6), soluble IL-6 receptor (sIL-6R), tumor necrosis factor-alpha-receptor (TNF-RII), and soluble intercellular adhesion molecule (sICAM) did not differ between those with and without depression.