Neural basis for behavioral plasticity during the parental life-stage transition in mice

Abstract

Parental care plays a crucial role in the physical and mental well-being of mammalian offspring. Although sexually naïve male mice, as well as certain strains of female mice, display aggression toward pups, they exhibit heightened parental caregiving behaviors as they approach the time of anticipating their offspring. In this Mini Review, I provide a concise overview of the current understanding of distinct limbic neural types and their circuits governing both aggressive and caregiving behaviors toward infant mice. Subsequently, I delve into recent advancements in the understanding of the molecular, cellular, and neural circuit mechanisms that regulate behavioral plasticity during the transition to parenthood, with a specific focus on the sex steroid hormone estrogen and neural hormone oxytocin. Additionally, I explore potential sex-related differences and highlight some critical unanswered questions that warrant further investigation.

Keywords: estrogen; hypothalamus; oxytocin; paternal behaviors; preoptic area.

Figure 1

Limbic neurons responsible for infanticide and parental behaviors in mice. The distinct neural subtypes accountable for infanticide are depicted in magenta, whereas those fostering parental behaviors are illustrated in blue. Refer to the text for abbreviations and detailed information on connectivity.

Figure 2

A circuit mechanism to facilitate paternal behaviors by PVH^OT neurons. Illustration depicting alterations in neural circuitry within the brains of paternal mice and the oxytocin-mediated facilitation of caregiving behavior (Inada et al., 2022a). The downstream neural processes associated with OT in promoting paternal behaviors remain unidentified, as denoted by the red question mark.