Paternal care in rodents: Ultimate causation and proximate mechanisms

Abstract

The evolution of paternal care in rodents has intrigued biologists for over decades. In this paper, both ultimate (adaptive significance, evolution) and proximate (ontogeny, mechanisms) questions related to the emergence and maintenance of male paternal care are reviewed. Paternal care is thought to be a consequence of social monogamy, but no definitive hypothesis adequately explains the evolution of paternal behavior in rodents. The onset, activation and maintenance of paternal care are shown to be governed by complex interactions in neuroendocrine systems that change during ontogeny. Depending on the species, different components of male experience as well as different exogenous cues are likely to be involved in the organization and activation of paternal behavior. Several hormones, including steroids (testosterone, estradiol, progesterone) and neuropeptides (prolactin, vasopressin, oxytocin), are involved in the onset, the maintenance, or both the onset and the maintenance of parental behavior, including direct paternal care. The effect of testosterone was found to be not universal and, moreover, species-specific. As for estrogens and neuropeptides, further investigations are needed to better understand the role of these hormones in activation and maintenance of rodent paternal behavior. Current research shows that male parental care in rodents is, to a great extent, an epigenetic phenomenon, and future studies will focus on the epigenetic modifications that can affect the paternal behavior in rodents. How to cite this article: Gromov V.S. 2020. Paternal care in rodents: ultimate causation and proximate mechanisms // Russian J. Theriol. Vol.19. No.1. P.1–20. doi: 10.15298/rusjtheriol.19.1.01.