Regulation of Maternal Care by Corticotropin-Releasing Factor Receptors in the Dorsal Raphe Nucleus in Mice

We previously reported that the dorsal raphe nucleus (DRN) was involved in the regulation of maternal care in lactating female mice. The DRN receives multiple innervations from a variety of the brain regions. Corticotropin-releasing factor (CRF) Type 1 and Type 2 receptors are distributed in the DRN. Both receptors have been implicated in regulating negative aspects including stress, fear, and anxiety. However, it remains unknown how CRF receptors in the DRN regulate maternal care. In the present study, we investigated how CRF receptors in the DRN is involved in regulating maternal care in lactating female mice. Injection of antalarmin or antisauvagine-30, which is an antagonist of CRF Type 1 or Type 2 receptor, respectively, into the DRN increased the latency to retrieving pups into the nest and to crouching over pups, and decreased the duration of crouching over pups, indicating that blockage of CRF receptor signaling in the DRN decreased maternal care. Each treatment did not affect anxiety-related behaviors, which were assayed using the hole-board test. These results suggest that CRF receptor signaling in the DRN positively regulates maternal care in lactating female mice.