Paternal Care Research Articles

Interplay of paternal caregiving and screen use habits on early childhood development and children’s tantrums

BackgroundThis study aims to examine the association for paternal care and father-child screen use with early childhood development and children’s temper tantrums.MethodStudy file included questions about paternal characteristics, child care, father-child screen habits, and utilized the UNICEF Early Childhood Development Index (ECDI). Factors influencing ECDI-on-track status and children’s responses when screen use was restricted were investigated with Chi-square test and multiple logistic regression.ResultsThe study included 464 fathers having children aged 3–4 years. The findings showed that 89.7% of the children were on track in three out of the four ECDI subgroups. When screen use was restricted, 55.6% of the children engaged in another activity, while 44.4% reacted by crying. Multiple logistic regression analysis revealed that the father’s education level, the child’s age and gender, the starting age for screen usage, the child’s reaction to screen restriction, and having three or more books were associated with ECDI. Furthermore, the child’s reaction to screen restriction was related to the child’s and father’s screen time, the presence of three or more books, the adequacy of care, and being on track in the literacy-numeracy ECDI subgroup.ConclusionScreen usage habits significantly impact early childhood development and children’s reactions to screen restrictions. These findings underscore the importance of educating fathers about the effects of their own and their child’s media habits, the quality of fatherly caregiving, and the presence of books in fostering positive child development.

Postpartum Mental Health Care Use Among Parents During Simultaneous Parental Leave

Flexible parental leave schemes can help families balance work, childcare, and postpartum treatment, including treatment for mental health. In Sweden, both parents are eligible to use parental leave simultaneously in the first year after birth; however, the consequences for postpartum mental health care uptake remain underinvestigated. To examine the association between parents' use of simultaneous parental leave and their use of postpartum mental health care in Sweden. This cohort study obtained baseline data from national registries in Sweden, including live births of singleton offspring between January 1, 2014, to December 31, 2015, and simultaneous parental leave use (any vs none) in the 12 months after birth. The population-based sample was composed of parental dyads (mothers and fathers) who were eligible for simultaneous parental leave and were followed up from January 1, 2015, to December 31, 2016. Statistical analyses were conducted between December 15, 2023, and August 14, 2024. Simultaneous parental leave use up to 12 months post partum. Total population register data were used to identify maternal and paternal outpatient care visits for mental health (substance use disorder [SUD], mood or affective disorders, and stress-related disorders) and psychotropic prescription dispensations (antidepressants and anxiolytics) during the first postpartum year. Logistic regression was applied to estimate the odds of these outcomes by simultaneous parental leave use, controlling for parents' age, sociodemographic characteristics, and prebirth mental health care use. Robustness analyses using propensity score matching were performed. The sample comprised 207 283 parental dyads, of whom 153 342 (74.0%) did not use simultaneous parental leave in the first postpartum year and 53 941 (26.0%) did. Among those who used simultaneous parental leave, the mean (SE) age at childbirth was 29.63 (0.02) years for mothers and 32.80 (0.03) years for fathers. Compared with mothers who did not use parental leave simultaneously with their partners, mothers who did were more likely to receive antidepressant prescriptions in the first postpartum year (odds ratio [OR], 1.07; 95% CI, 1.02-1.11). Fathers who used simultaneous parental leave vs those who did not had increased odds of SUD-related outpatient care visits (OR, 1.10; 95% CI, 1.02-1.20). Longer simultaneous parental leave was associated with greater odds of mental health care use for both parents, and earlier leave was associated with greater odds of health care use by mothers. Findings for mothers, but not fathers, remained significant in robustness analyses using propensity score matching. This cohort study found that simultaneous parental leave use was associated with greater health care uptake for postpartum mental health conditions in both mothers and fathers. This finding supports the need to consider the benefits of generous family policies as well as the risks of structural obstacles to postpartum mental health care access across the world.

Exploring attachment and couple relationships in endometriosis: A pilot study

Introduction: Endometriosis is the therapeutic and clinical complexity extends beyond its effects on the body’s organic system, with psychological and social impacts. However, studies analyzing the quality of attachment and couple adjustment, beyond the effects on sexuality and fertility, are currently lacking. Methods: The main objective of this study was to investigate the quality of past attachment by means of the Parental Bonding Instrument, current attachment through the Relationship Questionnaire, and the perception of couple quality and satisfaction by means of the Dyadic Adjustment Scale, in a sample of 68 women aged between 23 and 54 years. Results: The analysis revealed that women with endometriosis reported experiencing greater paternal and maternal control, and less paternal care compared to those in the control group. Moreover, women in the endometriosis group exhibited a higher degree of insecure attachment in adult intimate relationships when compared to the predominantly secure control group. Regarding the DAS, women with endometriosis reported lower scores than the control group. Conclusion: Despite the limitations of a pilot study, it provides a foundational basis for future research aiming to explore endometriosis within the context of women’s relationships. It also contributes to the planning of prevention and support programs for significant figures in women’s lives.

Current status of paternal mental health care in obstetric institutes in Japan.

SynopsisThere should be an urgent need to establish a mental health care system for partners in Japan.

Effects of Nest‐Site Availability on Male–Male Competition and the Foraging Costs of Egg Attendance in an Arachnid With Exclusive Paternal Care

ABSTRACTNatural cavities are monopolizable resources used as nest sites across many species exhibiting exclusive male care. However, our understanding of how the availability of this type of reproductive site influences male–male competition and the foraging costs associated with parental care is limited and based on studies of fish. The harvestman Magnispina neptunus offers the opportunity to explore these questions in invertebrates because males defend natural cavities used as oviposition sites and provide exclusive parental care. We hypothesized that low nest availability would increase male–male competition and the foraging costs of egg attendance. To test this hypothesis, we collected observational data in the field and conducted a laboratory experiment with two groups, low and high nest availability. Field data indicate natural cavity scarcity, as only 50% of the males were nest holders. Larger males were more likely to hold nests in the field, but body size did not predict nest ownership in the laboratory. In the field, nests with openings smaller than average were equally occupied by small and large males, while nests with openings larger than average were occupied almost exclusively by large males. The nest opening in the laboratory experiment was adjusted to be equal to the average found in the field, which may have increased nest defensibility, regardless of male size. Thus, prior residency may outweigh body size in determining nest possession. Because nest owners seem to have an advantage over intruders, the costs of abandoning a nest are likely high. This may explain why the frequency of nest takeovers and foraging outside the nests did not differ between experimental groups. In conclusion, although underexplored in empirical studies, external factors, such as the opening size of cavities defended by males of many species with resource‐defense mating systems, may play a key role in the defensibility of nest sites.

Clutch attendance and call parameters are linked to mating success in a glassfrog with paternal care.

Females of some species improve their reproductive success not only by being choosy and selecting males with certain traits, but also by sequentially mating with multiple males within one reproductive season. However, it is relatively unknown whether females also evaluate parental care during mate choice and, if they do, whether males actively communicate their care status to approaching females. We monitored a natural population of the glassfrog Hyalinobatrachium valerioi, a species with sequential polyandry and paternal care, to assess the role of parental care and advertisement calling on male mating success. Using field observations and acoustic analysis, we found that even in this species which has single-note calls, variations in call parameters allow for individual discrimination. Calling was strongly associated with mating success in H. valerioi males. Males with longer calls achieved the highest total mating success over the entire study period, indicating that females might have a preference for longer calls. Moreover, active calling and the presence of clutches were both linked to male mating success on a given night, although we cannot fully exclude that the link between presence of clutches and mating success is due to attractive call features alone. Call parameters differed between males when they were calling on top of their clutches, compared to sitting on the leaf directly, which might provide reliable cues about parental state to approaching females. These findings demonstrate the prominent role of acoustic communication and female choice in a species with male parental care and sequential polyandry.

Perceived parental rearing styles and depression in Chinese adolescents: the mediating role of self-compassion.

Adolescence is a period characterized by rapid biological and psychological change, and adolescents have a heightened risk of depression. Parental rearing is an important influencing factor for depression in adolescence. However, the mechanism of influence needs further exploration. A total of 1839 adolescents were recruited from a junior and a senior high school in Zhongshan City, Guangdong Province, China. They were requested to completed the Parental Bonding Instrument (PBI), Self-Compassion Scale (SCS), and Depression Anxiety and Stress Scale-21(DASS-21). Adolescents recalled their mothers as being more caring and controlling than their fathers. Parental care (maternal care, paternal care) and parental encouragement of autonomy (maternal encouragement of autonomy, paternal encouragement of autonomy) were both negative predictors of depression, while parental control (maternal control, paternal control) was positive predictor of depression. Self-compassion mediated all relationships between parental rearing styles (parental care, parental encouragement of autonomy, and parental control) and depression but played different mediating roles (complete or incomplete mediating role) in different relationships. Self-compassion plays a mediator role in all relationships between perceived parental rearing styles (parental care, parental encouragement of autonomy, and parental control) and depression. Adolescents who grown up with less parental care, less parental encouragement of autonomy, and high parental control deserve special attention. Educators and clinicians could help those adolescents reduce the occurrence of depression by increasing their level of self-compassion.

Paternal behavior in captive fat-tailed dwarf lemurs (Cheirogaleus medius) is preserved under socially relevant conditions.

Fat-tailed dwarf lemurs (Cheirogaleus medius), primates endemic to Madagascar, are obligate hibernators that form stable, lifelong pairs in the wild. Given the temporal constraints imposed by seasonal hibernation, infant dwarf lemurs must grow, develop, and wean within the first two months of life. Maternal as well as paternal infant care, observed in the wild, has been deemed critical for infant survival. Given the importance of fathers' involvement in early infant care, we expect this behavior to persist even under captive conditions. At the Duke Lemur Center, in Durham NC, we observed two families of fat-tailed dwarf lemurs and focused on the behavior of adult males within the first two months of the infants' lives. We report evidence of paternal involvement, including babysitting, co-feeding, grooming, accompanying, and leading infants, consistent with observations from the wild. As expected, paternal babysitting decreased as infants gained independence, while co-feeding increased. Supplemental anecdotes, video recorded by observers, also highlight clear cases of involvement by both parents, and even older siblings, in safeguarding and socializing new infants. We argue that maintaining captive fat-tailed dwarf lemur populations under socially and ecologically relevant conditions facilitates the full expression of physiological and behavioral repertoires. Most importantly, it also allows dwarf lemurs to realize their species' potential and become robust proxies of their wild kin.

Attachment Styles and Parenting Attitudes in Adults With "Pseudo-Attention-Deficit/Hyperactivity Disorder".

Background The number of individuals who experience the onset of attention-deficit/hyperactivity disorder (ADHD)-like symptoms after the age of 12 years has been growing, which does not meet the diagnostic criteria for adult ADHD. We designated this condition as "pseudo-ADHD" and investigated its psychological implications by comparing the parenting attitudes in childhood and attachment styles among individuals with "pseudo-ADHD," those with adult ADHD, and healthy controls. Methods We conducted an online cross-sectional survey of adults aged 18 years. Participants in the analysis included individuals with "pseudo-ADHD" (n = 46), adults with ADHD (n = 23), and healthy controls (n = 758). The Parental Bonding Instrument (PBI) was used to evaluate parenting attitudes, and the Experiences in Close Relationships Inventory for the Generalized Other (ECR-GO) was used to evaluate attachment styles. One-way analysis of variance was performed to compare the PBI and ECR-GO scores among the three groups. Results Regarding the PBI scores, a significant main effect of group was found for the paternal care scores (p = 0.002), and the "pseudo-ADHD" group did not differ significantly from the adult ADHD group or healthy control group (p = 0.378, p = 0.228, respectively). A significant main effect of the group was found for the maternal care scores (p < 0.001). The "pseudo-ADHD" group scored significantly lower than the adult ADHD group (p = 0.005), whereas there was no significant difference compared to the healthy control group (p = 1.000). A significant main effect of the group was also found for the paternal overprotection scores (p < 0.001). The "pseudo-ADHD" group scored significantly lower than the adult ADHD group (p = 0.002), whereas there was no significant difference compared to the healthy control group (p = 0.571). A significant main effect of group was found for the maternal overprotection scores (p < 0.001), and the "pseudo-ADHD" group did not differ significantly from either the adult ADHD group or the healthy control group (p = 0.060, p = 0.161, respectively). Regarding ECR-GO scores, a significant main effect of group was found for the fear of abandonment score (p < 0.001), and the "pseudo-ADHD" group scored significantly lower than the adult ADHD group (p < 0.001) and significantly higher than the healthy control group (p = 0.005). Conclusion This study suggested that the parenting attitudes of parents of individuals with "pseudo-ADHD" were not different from those of the healthy controls. For attachment styles, the fear of abandonment was higher in individuals with "pseudo-ADHD" than in healthy controls, but not as high as in patients with adult ADHD. This study highlights, for the first time, the importance of considering attachment styles in the diagnosis and treatment of individuals with ADHD symptoms in adulthood.

Females increase reproductive investment when mated to less sexually attractive males in a serially monogamous fish

Reproductive investment decision is an integral part of life-history theory. Differential allocation hypothesis predicts that females should increase investment when mated to high-quality males, conversely, reproductive compensation hypothesis predicts that females should increase investment when mated to low-quality males. Empirical research dominantly focuses on polygamous species and rarely on serially monogamous species. So, the question remains: which hypothesis does serially monogamous species fit? And if it fits reproductive compensation hypothesis, do females only compensate once or continuously for multiple times when mating to low-quality males? Here, we used a serially monogamous fish, the lined seahorse (Hippocampus erectus), to investigate the reproductive investment pattern of females in relation to male quality (measured by sexual attractiveness). We found that females allocated more resources into eggs when they mated to less-sexually-attractive males, indicating the investment pattern of lined seahorse falls in with the prediction of reproductive compensation hypothesis. This finding may imply that the sex role of seahorses is reversed, and female is the side imposed on a greater sexual selection pressure. On this basis, we compared the investment difference of females in two consecutive breeding events when mated to less-sexually-attractive males. We found that females allocated less resources into eggs in the second breeding than in the first one. Females reduced their reproductive compensation in the second breeding, which may be attributed to the improvement in the quality (e.g., paternal care ability) of their mates after the first breeding, thus eliminating the need for them to invest more in the second breeding.

Evolution of obligate asexuality in termites with mixed‐sex societies

AbstractMales are a ubiquitous feature of animals and play crucial roles beyond the contribution of gametes in some species (e.g., paternal care for offspring and nuptial gifts for females). In termites, colonies commonly consist of both male and female reproductives, workers, and soldiers (i.e., mixed‐sex societies), where males and females both play critical roles beyond reproduction (e.g., brood care, foraging, nest construction and maintenance, and colony defense). Male‐specific roles may also exist in termite colonies. While obligate asexuality had not been observed in any termite population until recently, all‐female asexual populations of the termite Glyptotermes nakajimai were reported in 2018. This was the first and only known case of evolutionary transition from mixed‐sex to all‐female asexual societies in animals. Here, asexual reproduction in termites is first reviewed, followed by a discussion of how and why G. nakajimai evolved obligate asexuality. The study of the evolution of obligate asexuality in termites with mixed‐sex societies is important because it may enhance our understanding of the significance of males in animal societies and populations.

Sexual selection and life history interact to influence the evolution of paternal care.

Parental care is essential to offspring survival in many species. Understanding why males of some species provide care, whereas others do not, has received substantial attention. Previous research has found that sexual selection can favor paternal care, yet we still do not fully understand why sexual selection favors male care in some species but not others. It is also unclear when paternal care versus other preferred male trait(s) will be favored by sexual selection. We hypothesize that sexual selection can interact with basic life history to influence the conditions under which paternal care and/or another preferred male trait will be favored by sexual selection. We used a mathematical approach in which males alone provide parental care and exhibit a non-care trait that is preferred in mate choice. Using this approach, we demonstrate that life-history characteristics (stage-specific mortality, fertilization success, gamete numbers) can interact with sexual selection to influence the evolution of paternal care and/or a preferred non-care trait. In particular, whether (1) adult mortality, egg mortality, and fertilization success are high versus low and (2) a tradeoff exists between paternal care and a non-care preferred trait will influence whether selection most strongly favors additional paternal care or a non-care preferred trait. In general, we would expect strong selection for more male care when it is preferred in mate choice. In some cases, mate preferences for paternal care can inhibit selection for a preferred non-care trait. Mate preferences for paternal care can also broaden the life-history conditions under which we would expect the elaboration of male care to occur.

The perceived quality of maternal care during childhood shapes attentional bias to infant faces in parents and nonparents.

While research has shown that the attentional bias to infant faces predicts the quality of infant care, the antecedents of this cognitive process have been less established. In particular, it remains unknown whether the attentional bias to infant faces might be affected by the interplay between different factors, including memories of past experiences of care, adults' sex, and the experience of parenthood. To extend previous results, we examined the attentional bias to infant faces in a mixed sample of parents (n = 99) and nonparents (n = 102), and whether it varied in relation to parental status, sex, the quality of past experiences of care, and the interactions between these factors. A modified go/no-go task was used to compare the effect of adult and infant faces in retaining adults' attention. Memories of past experiences of paternal and maternal care were collected using the short form of the Italian version of the Parental Acceptance-Rejection scale. Results confirmed that infant faces induced greater attentional interference compared to adult faces. A heightened attention to all types of faces was found in parents versus nonparent. Women, as compared to men, were slower in the task performance, and allocated more attention to infant versus adult faces. Consistent with previous evidence, the attentional prioritization of infant faces varied in relation to previous experiences of care with one's own mother; individuals who remembered a more accepting maternal care allocated more attention to infant versus adult faces. Parental status did not modulate this effect, but sex of participants did. Grounded in the interpersonal acceptance-rejection theory (IPARTheory), this study provides new insights for discerning processes that might regulate global adult caregiving. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

A pheromone receptor in cichlid fish mediates attraction to females but inhibits male parental care

Reproductive behaviors differ across species, but the mechanisms that control variation in mating and parental care systems remain unclear. In many animal species, pheromones guide mating and parental care. However, it is not well understood how vertebrate pheromone signaling evolution can lead to new reproductive behavior strategies. In fishes, prostaglandin F2α (PGF2α) drives mating and reproductive pheromone signaling in fertile females, but this pheromonal activity appears restricted to specific lineages, and it remains unknown how a female fertility pheromone is sensed for most fish species. Here, we utilize single-cell transcriptomics and CRISPR gene editing in a cichlid fish model to identify and test the roles of key genes involved in olfactory sensing of reproductive cues. We find that a pheromone receptor, Or113a, detects fertile cichlid females and thereby promotes male attraction and mating behavior, sensing a ligand other than PGF2α. Furthermore, while cichlid fishes exhibit extensive parental care, for most species, care is provided solely by females. We find that males initiate mouthbrooding parental care if they have disrupted signaling in ciliated sensory neurons due to cnga2b mutation or if or113a is inactivated. Together, these results show that distinct mechanisms of pheromonal signaling drive reproductive behaviors across taxa. Additionally, these findings indicate that a single pheromone receptor has gained a novel role in behavior regulation, driving avoidance of paternal care among haplochromine cichlid fishes. Lastly, a sexually dimorphic, evolutionarily derived parental behavior is controlled by central circuits present in both sexes, while olfactory signals gate this behavior in a sex-specific manner.

The transgenerational consequences of paternal social isolation and predation exposure in threespined sticklebacks.

Parents routinely encounter stress in the ecological environment that can affect offspring development (transgenerational plasticity: TGP); however, parents' interactions with conspecifics may alter how parents respond to ecological stressors. During social buffering, the presence of conspecifics can reduce the response to or increase the speed of recovery from a stressor. This may have cascading effects on offspring if conspecifics can mitigate parental responses to ecological stress in ways that blunt the transmission of stress-induced transgenerational effects. Here, we simultaneously manipulated both paternal social isolation and experience with predation risk prior to fertilisation in threespined stickleback (Gasterosteus aculeatus). We generated offspring via in-vitro fertilisation to allow us to isolate paternal effects mediated via sperm alone (i.e. in the absence of paternal care). If social buffering mitigates TGP induced by paternal exposure to predation risk, then we expect the transgenerational effects of predation exposure to be weaker when a conspecific is present compared to when the father is isolated. Offspring of predator-exposed fathers showed reduced anxiety-like behaviour and tended to be captured faster by the predator. Fathers who were socially isolated also had offspring that were captured faster by a live predator, suggesting that paternal social isolation may have maladaptive effects on how offspring respond to ecological stressors. Despite additive effects of paternal social isolation and paternal predation risk, we found no evidence of an interaction between these paternal treatments, suggesting that the presence of a conspecific did not buffer fathers and/or offspring from the effects of predation risk. Our results suggest that socially induced stress is an important, yet underappreciated, mediator of TGP and can elicit transgenerational effects even in species that do not form permanent social groups. Future studies should therefore consider how the parental social environment can affect both within and trans-generational responses to ecological stressors.

Parental care and overprotection predict worry and anxiety symptoms in emerging adult students

Anxiety disorders represent a prevalent mental health concern, with escalating rates, especially among emerging adults. University students, in particular, face a myriad of academic and life stressors that can amplify feelings of worry and anxiety. While early parental bonding seem to predict anxiety disorders later in life, the applicability to emerging adult students and its applicability to predict sub-clinical and transdiagnostic anxiety features remain unclear. This study aims to examine i) the relationship between demographic variables and key features of anxiety disorders (i.e., worry and anxiety symptoms); and ii) the predictive association between early parental bonding and anxiety-related features. A sample of 370 university students in Italy (n = 279 females; M age = 20.84 years, SD age = 1.81 years) completed the Parental Bonding Instrument, the Penn State Worry Questionnaire, and the Beck Anxiety Inventory. Females reported higher levels of worry and anxiety compared to males. Significantly higher worry and anxiety symptoms were reported by individuals who experienced affectionless control (low care and high overprotection) as compared to those exposed to optimal parenting (high care and low overprotection). Predictive models indicated that scores of parental care (i.e., the principal component between maternal and paternal care scores) and parental overprotection (i.e., the principal component between maternal and paternal overprotection scores) are robust predictors of worry and anxiety symptoms. However, this relationship showed a gender-specific pattern: lower parental care was more significant in predicting anxiety features in males, while high overprotection was more significant in females. The findings contribute to the comprehension of the risk factors influencing the susceptibility of emerging adult students to anxiety disorders.

Paternal care plasticity: males care more for early- than late-developing embryos in an arboreal breeding treefrog

BackgroundParental care benefits offspring but comes with costs. To optimize the trade-off of costs and benefits, parents should adjust care based on intrinsic and/or extrinsic conditions. The harm to offspring hypothesis suggests that parents should invest more in younger offspring than older offspring because younger offspring are more vulnerable. However, this hypothesis has rarely been comprehensively tested, as many studies only reveal an inverse correlation between parental care and offspring age, without directly testing the effects of offspring age on their vulnerability. To test this hypothesis, we studied Kurixalus eiffingeri, an arboreal treefrog with paternal care. We first performed a field survey by monitoring paternal care during embryonic development. Subsequently, we conducted a field experiment to assess the prevalence of egg predators (a semi-slug, Parmarion martensi) and the plasticity of male care. Finally, we conducted a laboratory experiment to assess how embryo age affects predation by P. martensi.ResultsOur results showed that (1) male attendance and brooding frequency affected embryo survival, and (2) males attended and brooded eggs more frequently in the early stage than in the late stage. The experimental results showed that (3) males increased attendance frequency when the predators were present, and (4) the embryonic predation by the semi-slug during the early was significantly higher than in the late stage.ConclusionsOur findings highlight the importance of paternal care to embryo survival, and the care behavior is plastic. Moreover, our results provide evidence consistent with the predictions of the harm to offspring hypothesis, as males tend to care more for younger offspring which are more vulnerable.

Effects of acute inhibition of dopamine β-hydroxylase on neural responses to pups in adult virgin male California mice (Peromyscus californicus)

The neural mechanisms underlying paternal care in biparental mammals are not well understood. The California mouse (Peromyscus californicus) is a biparental rodent in which virtually all fathers are attracted to pups, while virgin males vary widely in their behavior toward unrelated infants, ranging from attacking to avoiding to huddling and grooming pups. We previously showed that pharmacologically inhibiting the synthesis of the neurotransmitter norepinephrine (NE) with the dopamine β-hydroxylase inhibitor nepicastat reduced the propensity of virgin male and female California mice to interact with pups. The current study tested the hypothesis that nepicastat would reduce pup-induced c-Fos immunoreactivity, a cellular marker of neural activity, in the medial preoptic area (MPOA), medial amygdala (MeA), basolateral amygdala (BLA), and bed nucleus of the stria terminalis (BNST), brain regions implicated in the control of parental behavior and/or anxiety. Virgin males were injected with nepicastat (75 mg/kg, i.p.) or vehicle 2 hours prior to exposure to either an unrelated pup or novel object for 60 minutes (n = 4–6 mice per group). Immediately following the 60-minute stimulus exposure, mice were euthanized and their brains were collected for c-Fos immunohistochemistry. Nepicastat reduced c-Fos expression in the MeA and MPOA of pup-exposed virgin males compared to vehicle-injected controls. In contrast, nepicastat did not alter c-Fos expression in any of the above brain regions following exposure to a novel object. Overall, these results suggest that the noradrenergic system might influence MeA and MPOA function to promote behavioral interactions with pups in virgin males.

From molecular variations to behavioral adaptations: Unveiling adaptive epistasis in primate oxytocin system.

Our primary objective was to investigate the variability of oxytocin (OT) and the GAMEN binding motif within the LNPEP oxytocinase in primates. We sequenced the LNPEP segment encompassing the GAMEN motif in 34 Platyrrhini species, with 21 of them also sequenced for the OT gene. Our dataset was supplemented with primate sequences of LNPEP, OT, and the oxytocin receptor (OTR) sourced from public databases. Evolutionary analysis and coevolution predictions were made followed by the macroevolution analysis of relevant amino acids associated with phenotypic traits, such as mating systems, parental care, and litter size. To account for phylogenetic structure, we utilized two distinct statistical tests. Additionally, we calculated binding energies focusing on the interaction between Callithtrix jacchus VAMEN and Pro8OT. We identified two novel motifs (AAMEN and VAMEN), challenging the current knowledge of motif conservation in placental mammals. Coevolution analysis demonstrated a correlation between GAMEN, AAMEN, and VAMEN and their corresponding OTs and OTRs. Callithrix jacchus exhibited a higher binding energy between VAMEN and Pro8OT than orthologous molecules found in humans (GAMEN and Leu8OT). The coevolution of AAMEN and VAMEN with their corresponding OTs and OTRs suggests a functional relationship that could have contributed to specific reproductive and adaptive behaviors, including paternal care, social monogamy, and twin births, prominent traits in Cebidae species, such as marmosets and tamarins. Our findings underscore the coevolution of taxon-specific amino acids among the three studied molecules, shedding light on the oxytocinergic system as an adaptive epistatic repertoire in primates.

Androgen and glucocorticoid profiles throughout extended uniparental paternal care in the eastern hellbender salamander (Cryptobranchus a. alleganiensis)

The behavioral endocrinology associated with reproduction and uniparental male care has been studied in teleosts, but little is known about hormonal correlates of uniparental male care in other ectotherms. To address this gap, we are the first to document the seasonal steroid endocrinology of uniparental male hellbender salamanders during the transition from pre-breeding to nest initiation, and through the subsequent eight months of paternal care. In doing so, we investigated the correlates of nest fate and clutch size, exploring hellbenders’ alignment with several endocrinological patterns observed in uniparental male fish. Understanding the endocrinology of hellbender paternal care is also vital from a conservation perspective because high rates of nest failure were recently identified as a factor causing population declines in this imperiled species. We corroborated previous findings demonstrating testosterone and dihydrotestosterone (DHT) to be the primary androgens in hellbender reproduction, and that cortisol circulates as the most abundant glucocorticoid. However, we were unable to identify a prolactin or a “prolactin-like” peptide in circulation prior to or during parental care. We observed ∼ 80 % declines in both primary androgens during the transition from pre-breeding to nest initiation, and again as paternal care progressed past its first month. In the days immediately following nest initiation, testosterone and DHT trended higher in successful individuals, but did not differ with males’ clutch size. We did not observe meaningful seasonality in baseline glucocorticoids associated with breeding or nesting. In contrast, stress-induced glucocorticoids were highest at pre-breeding and through the first two months of care, before declining during the latter-most periods of care as larvae approach emergence from the nest. Neither baseline nor stress-induced glucocorticoids varied significantly with either nest fate or clutch size. Both stress-induced cortisol and corticosterone were positively correlated with total length, a proxy for age in adult hellbenders. This is consistent with age-related patterns in some vertebrates, but the first such pattern observed in a wild amphibian population. Generally, we found that nesting hellbenders adhere to some but not all of the endocrinological patterns observed in uniparental male teleosts prior to and during parental care.