Seasonal adaptation of the Djungarian hamster (Phodopus sungorus) exhibits drastic changes of the annual body weight cycle, which is characterized by the development of central leptin resistance during long day photoperiod (LD, 16:8 h light dark cycle). The molecular mechanisms underlying these physiological changes remain largely unknown. We previously have shown that the canonical WNT/β-catenin signaling pathway is essential for central control of metabolism and the maintenance of leptin sensitivity in mice. In the current study we analyzed whether members of canonical WNT signaling are expressed in the hypothalamus of hamsters and furthermore are under photoperiodic control. Therefore, hypothalamic mRNA expression of various WNT components was analyzed by performing in situ hybridization with brains of hamsters acclimated to both LD and short day photoperiod (SD, 8:16 h light dark cycle) for eight weeks. Gene expression of the WNT antagonist secreted frizzled-related protein 2 (SFRP-2) was decreased in the arcuate nucleus of SD acclimated hamsters relative to hamsters in LD, whereas gene expression of the WNT target gene Axin-2 was inversely regulated. Measurements of circadian regulation of theses genes and the involvement of other WNT components in seasonal body weight regulation are currently in progress. In conclusion, the expression pattern of the investigated genes involved in WNT signaling strongly indicates that this pathway is functionally impaired in the hypothalamus of hamsters during LD and is reinstated during SD photoperiod. These data suggest that the canonical WNT pathway might be involved in the seasonal regulation of central leptin sensitivity, possibly driving this physiological adaptation.