The Role of Olfactory Genes in the Expression of Rodent Paternal Care Behavior

Abstract

Olfaction is the dominant sensory modality in rodents, and is crucial for regulating social behaviors, including parental care. Paternal care is rare in rodents, but can have significant consequences for offspring fitness, suggesting a need to understand the factors that regulate its expression. Pup-related odor cues are critical for the onset and maintenance of paternal care. Here, I consider the role of olfaction in the expression of paternal care in rodents. The medial preoptic area shares neural projections with the olfactory and accessory olfactory bulbs, which are responsible for the interpretation of olfactory cues detected by the main olfactory and vomeronasal systems. The olfactory, trace amine, membrane-spanning 4-pass A, vomeronasal 1, vomeronasal 2 and formyl peptide receptors are all involved in olfactory detection. I highlight the roles that 10 olfactory genes play in the expression of direct paternal care behaviors, acknowledging that this list is not exhaustive. Many of these genes modulate parental aggression towards intruders, and facilitate the recognition and discrimination of pups in general. Much of our understanding comes from studies on non-naturally paternal laboratory rodents. Future studies should explore what role these genes play in the regulation and expression of paternal care in naturally biparental species.

Behavioral trajectories of aging prairie voles (Microtus ochrogaster): Adapting behavior to social context wanes with advanced age

“…Although no studies have specifically examined social discrimination in aging prairie voles, a previous study found that olfactory discrimination abilities are preserved in age and are relatively equivalent in 2-, 10-, and 23-month-old mice [ 66 ]. Indeed, olfactory discrimination abilities are crucial to survival in most rodents [ 67 , 68 ], and it is likely highly adaptable to exhibit preserved sensory function throughout the lifespan of a rodent. Although somewhat different from our findings in the present study, two previous studies using C56BL/6J male mice found that PND180-365 mice engaged in less social contact in a social interaction test with a novel, same-sex juvenile compared to mice aged PND60-150 [ 48 , 69 ].…”

Neurobiology of Maternal Behavior in Nonhuman Mammals: Acceptance, Recognition, Motivation, and Rejection

“…BNST and MeA project to the mPOA, which in turn projects to the lateral preoptic area (LPOA) and substantia innominata (SI). LPOA and SI also send efferents to the ventral tegmental area (VTA), which sends dopaminergic projections to the nucleus accumbens (NAcc) [ 71 , 72 ]. With regard to volatile odor molecules (those that have a low boiling point and evaporate easily at room temperature), they are detected in the roof of the nasal cavity by the main olfactory epithelium (MOE), where olfactory sensory neurons are located.…”

Odour-based social recognition in Damaraland mole-rats, Fukomys damarensis

“…The sensory capacities of the olfactory system have been particularly well studied in rodents, stimulated by the long tradition of work with laboratory mice and rats (Ferguson, Young, & Insel, 2002;Johnston, 2003), and there is evidence from several rodent taxa that olfaction is used in a variety of social contexts. Odour cues can denote sex, reproductive status (Brennan & Kendrick, 2006) and group membership (Heth, Todrank, & Burda, 2002), mediating a suite of social behaviours involved in mate choice, maternal care, competition and cooperation (Rymer, 2020;Stockley, Bottell, & Hurst, 2013;Willis & Poulin, 2000). For example, in communally nesting house mice, Mus musculus domesticus, females often form nursing partnerships to rear offspring, and prefer nest partners with their own major urinary protein genotype (Green et al, 2015), assessed using unique odour 'signatures' (Roberts et al, 2018).…”