Displays of paternal mouse pup retrieval following communicative interaction with maternal mates

Abstract

Compared with the knowledge of maternal care, much less is known about the factors required for paternal parental care. Here we report that new sires of laboratory mice, though not spontaneously parental, can be induced to show maternal-like parental care (pup retrieval) using signals from dams separated from their pups. During this interaction, the maternal mates emit 38-kHz ultrasonic vocalizations to their male partners, which are equivalent to vocalizations that occur following pheromone stimulation. Without these signals or in the absence of maternal mates, the sires do not retrieve their pups within 5 min. These results show that, in mice, the maternal parent communicates to the paternal parent to encourage pup care. This new paradigm may be useful in the analysis of the parental brain during paternal care induced by interactive communication.

Effects of electrical lesions of the medial preoptic area and the ventral pallidum on mate-dependent paternal behavior in mice

“…When mouse sires are continuously housed in the maternal cage with their mates and pups for three to five days prior to and after parturition, they exhibit signs of maternal-like parental care. Furthermore, when separated from their pups for 10 min and co-housed with the dam in a new cage, sires exhibited retrieval behavior when reunited with their pups [14]. We also found that expression of male parental behavior is triggered by olfactory and unique 38-kHz ultrasonic http://dx.doi.org/10.1016/j.neulet.2014.03.078 0304-3940/© 2014 Elsevier Ireland Ltd. All rights reserved.…”

“…They were then returned to their home cage with five selected pups placed at the opposite side of the nest arena, as illustrated by the schematic in Fig. 1 of Liu et al [14]. As an index of parental behavior, two experts observed the retrieval behavior (the percentage of sires that exhibited retrieval) for 10 min after the reunion of the parent with his/her own pups.…”

“…Males and females of the Slc:ICR line were obtained from Japan SLC Inc. (Hamamatsu, Japan) and kept in our laboratory, as described previously [14,19]. Virgin males and females were paired on postnatal days 45-55.…”

“…To address this issue, we use a classical deletion method, the electrolytic brain lesion (EBL) technique, according to the details described by Lee and Brown [26], to determine the extent to which the mPOA and VP regions regulate paternal care in mice of the ICR strain [19], since we hypothesize that the brain lesions may affect paternity. We first focus on paternal behavior by lesioned sires mated with intact dams, because sires isolated alone do not display paternal behavior, dams inevitably care pups, and dams are needed for sires to induce paternal care [14]. Next, we test pup care behavior and pup survival in the sire plus dam lesion groups to confirm if they are behaviorally different from the sire-only-lesion groups.…”

“…However, uniparental male mice that are forced to live together exhibit maternal-like behavior, including providing protection and warmth to offspring [13]. We recently developed a co-housing paradigm to study paternal behavior of the mouse ICR strain [14][15][16]. When mouse sires are continuously housed in the maternal cage with their mates and pups for three to five days prior to and after parturition, they exhibit signs of maternal-like parental care.…”