Approaches to anorexia in rodents: focus on the anx/anx mouse

Eating disorders constitute major medical health problems in the western world. Even though little is known about the mechanisms behind abnormal eating behavior, it has become clear that the central nervous system (CNS), particularly the hypothalamus, plays a significant role. The anorexic anx/anx mouse is a unique model for studying food intake and energy expenditure. The anx mutation is linked to marked alterations in hypothalamic distributions of signal substances known to have potent regulatory roles in the control of food intake. We have identified a mutation in anx/anx mice that is likely to cause the anorectic phenotype. Using RNA profiling, we have found 29 genes with differential expression in the anx/anx mouse brain. The anx gene, its protein product or molecules in the anx pathway may thus be interesting targets for development of new pharmaceuticals for the treatment of eating disorders. Based on the histochemical alterations found in the anx/anx mouse, we hypothesised and showed that many sera from anorectic/bulimic patients contain antibodies that bind specifically to the hypothalamic food intake regulatory system in rat. This finding represents a novel research avenue that may lead to a better understanding of eating disorders. It also suggests that targeted immunological approaches may be used in therapy.