Mammalian females deliver immature pups, which obtain energy only from milk before weaning. Although lactation increases the risk of malnutrition under negative energy conditions, dams cannot afford to abandon their pups for achieving the transfer of their genome to the next generation. If dams can survive, they may nurture their pups even under negative energy conditions. The adequate behavior, namely maternal care including nest building, retrieving behavior, and crouching behavior, is required for nurturing pups in mice. In the present study, we examined the neuronal mechanism for regulating maternal care under food-restricted conditions. BALB/c dams displayed maternal care 3 h, but not 8 h, after food deprivation. We examined whether oxytocin signaling in the dorsal raphe nucleus (DRN), which is involved in nutritional state-dependent regulation of maternal care, mediates display of maternal care in fasted dams. The injection with 2 nmol L-368899, which is an oxytocin receptor antagonist, into the DRN inhibited maternal care in dams with 3-h-fasted, but not fed, dams, compared to the injection with saline. In contrast, the injection with 100 pmol oxytocin into the DRN recovered maternal care in 8-h-fasted dams. Fasting increased the number of oxytocin-positive cells in the paraventricular nucleus (PVN), but not the supraoptic nucleus, in the hypothalamus. In contrast, the number of oxytocinpositive neurons expressing c-Fos, a marker of neuronal activation, did not increase. In 4-h-and 9-h-fasted dams injected with a retrograde tracer, fluorogold, into the DRN, no oxytocin-positive neurons expressing both c-Fos and fluorogold was detected. Taken together, these results indicate that oxytocin signaling in the DRN is required for maternal care under negative energy conditions, and that oxytocin may not be transferred from the PVN to the DRN by synaptic transmission.