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Children’s physical, cognitive, and emotional maturation require adequate interactions and secure attachment with their primary caregivers. However, the causal relationships between parenting components and the aspects of infant attachment behaviors toward the caregiver remain unclear. New World monkey common marmosets provide an ideal model of human parent-infant relations because, like humans, infant care is shared among family members using intricate vocal communications. Combining the natural variations in parenting styles and subsecond-scale analyses of dyadic vocal and physical interactions, we demonstrate that marmoset infants signal their need by the social context-dependent use of call types and by exhibiting physical avoidance to rejective and neglectful caregivers. When deprived of an early social environment, infants cannot develop the adaptive use of attachment behaviors or age-appropriate autonomy. These data demonstrate the critical role of social contexts and developmental dynamics in physical and vocal attachment behaviors in infancy.TeaserMarmoset infants modulate their attachment behaviors toward each caregiver, according to their inherent parenting styles.

Oxytocin (Oxt) controls reproductive physiology and various kinds of social behaviors, but the exact contribution of Oxt to different components of parental care still needs to be determined. Here, we illustrate the neuroanatomical relations of the parental nurturing-induced neuronal activation with magnocellular Oxt neurons and fibers in the medial preoptic area (MPOA), the brain region critical for parental and alloparental behaviors. We used genetically-targeted mouse lines forOxt,Oxt receptor(Oxtr),vasopressin receptor 1a(Avpr1a),vasopressin receptor 1b(Avpr1b), andthyrotropin-releasing hormone(Trh) to systematically examine the role of Oxt-related signaling in pup-directed behaviors. TheOxtr-Avpr1a-Avpr1btriple knock-out (TKO), andOxt-Trh-Avpr1a-Avpr1bquadruple KO (QKO) mice were grossly healthy and fertile, except for their complete deficiency in milk ejection and modest deficiency in parturition secondary to maternal loss of theOxtorOxtrgene. In our minimal stress conditions, pup-directed behaviors in TKO and QKO mothers and fathers, virgin females and males were essentially indistinguishable from those of their littermates with other genotypes. However,OxtrKO virgin females did show decreased pup retrieval in the pup-exposure assay performed right after restraint stress. This stress vulnerability in theOxtrKO was abolished by the additionalAvpr1bKO. The general stress sensitivity, as measured by plasma cortisol elevation after restraint stress or by the behavioral performance in the open field (OF) and elevated plus maze (EPM), were not altered in theOxtrKO but were reduced in theAvpr1bKO females, indicating that the balance of neurohypophysial hormones affects the outcome of pup-directed behaviors.

Allogrooming, where an individual grooms another, has been extensively studied in various social animals to understand its role in the evolution of cooperation/prosociality. In existing studies in mammals, allogrooming has been suggested to exhibit not only a hygiene but also a social function. Allopreening, a topic of increasing interest in mammals but recently also in birds, has been studied mostly with mature animals. However, in some species immature individuals also show allopreening and its function remains poorly understood. Crows, Corvus spp., are an ideal model to study this phenomenon, because juveniles form year‐round aggregates during their long juvenile stage (e.g., throughout 3–4 years). Here, we investigated the function of allopreening in juvenile groups of wild‐caught large‐billed crows (C. macrorhynchos). Allopreening frequency and duration for three groups of wild‐caught juveniles were analysed to determine whether there was a symmetrical (i.e., reciprocal) or asymmetrical allopreening pattern, and if sex composition of the dyad and/or relative dominance of donor and recipient had an effect. We found that both the frequency and duration of male allopreening correlated with frequency of aggression. Allopreening between both males and females occurred unidirectionally from dominants to subordinates but not in the opposite direction. On the contrary, allopreening between a male and a female was found to be reciprocated, though the absolute frequency and duration were both greater in males than in females. These results suggest that the social function of allopreening in juvenile crows differs depending on the sex composition of the dyad, functioning as a dominance signal for same‐sex dyads, and serving a social bonding function for opposite‐sex dyads. These findings may reflect the potentially crucial roles of allopreening in within‐sex competition and opposite‐sex attraction during the 3 year‐long juvenile stage affecting future mate choice in lifelong monogamy.

Approximately 20%-30% of infants cry excessively and exhibit sleep difficulties for no apparent reason, causing parental stress and even triggering impulsive child maltreatment in a small number of cases.

Maternal mammals exhibit heightened motivation to care for offspring, but the underlying neuromolecular mechanisms have yet to be clarified. Here, we report that the calcitonin receptor (Calcr) and its ligand amylin are expressed in distinct neuronal populations in the medial preoptic area (MPOA) and are upregulated in mothers. Calcr+ MPOA neurons activated by parental care project to somatomotor and monoaminergic brainstem nuclei. Retrograde monosynaptic tracing reveals that significant modification of afferents to Calcr+ neurons occurs in mothers. Knockdown of either Calcr or amylin gene expression hampers risk-taking maternal care, and specific silencing of Calcr+ MPOA neurons inhibits nurturing behaviors, while pharmacogenetic activation prevents infanticide in virgin males. These data indicate that Calcr+ MPOA neurons are required for both maternal and allomaternal nurturing behaviors and that upregulation of amylin-Calcr signaling in the MPOA at least partially mediates risk-taking maternal care, possibly via modified connectomics of Calcr+ neurons postpartum.

Group living has both benefits and costs to individuals; benefits include efficient acquisition of resources, and costs include stress from social conflicts among group members. Such social challenges result in hierarchical dominance ranking among group members as a solution to avoid escalating conflict that causes different levels of basal stress between individuals at different ranks. Stress-associated glucocorticoid (corticosterone in rodents and birds; CORT) levels are known to correlate with dominance rank in diverse taxa and to covary with various social factors, such as sex and dominance maintenance styles. Although there is much evidence for sex differences in the basal levels of CORT in various species, the correlation of sex differences in basal CORT with dominance rank is poorly understood. We investigated the correlation between CORT metabolites (CM) in the droppings and social factors, including rank and sex, in a captive non-breeder group of crows. In this group, all the single males dominated all the single females, and dominance ranks were stable among single males but relatively unstable among single females. CM levels and rank were significantly correlated in a sex-reversed fashion: males at higher rank (i.e., more dominant) had higher CM, whereas females at higher rank exhibited lower CM. This is the first evidence of sex-reversed patterns of CM-rank correlation in birds. The results suggest that different mechanisms of stress-dominance relationships operate on the sexes in non-breeder crow aggregations; in males, stress is associated with the cost of aggressive displays, whereas females experience subordination stress due to males' overt aggression.

Efficient parental care is indispensable for survival of the mammalian offspring, and therefore both parents and offspring cooperate to achieve the best performance. For example, when parents transport altricial offspring, the offspring immediately respond by reducing its cry and movement in both human infants and rodent pups. This coordinated set of central, motor and cardiac responses is designated as the Transport Response (TR) and is shown to facilitate maternal carrying in rodents. The present study aims to investigate the core behavioural characteristics of mother-infant interaction, and to investigate the mechanisms underlying the mother-pup cooperation using pharmacological and genetic manipulations (i.e. Oprm1-/). Along with the clear developmental changes of the pups' immobility and posture during maternal carrying as previously reported, there were also adaptations in maternal strategies, particularly in positioning of foothold and oral grasp over the pup's body, with the pups' age and pup's behaviour. Tree-based models elucidated that both of these maternal variables as well as percentage of pups' struggle predict the time required for pup retrieval from a cup. When the sensory-motor control in pups was disturbed by pharmacological or genetic manipulations, these core behaviours were inefficiently performed and impede maternal retrieval. Mother-infant mutual fit is a complex construct where several intermingled mechanisms are involved. Thus mothers and infants, when interacting, should be considered together as one whole system in which any change in one side or the other, affects the output of the whole dyad. The outcome of the interaction relays on a specific dynamic pattern of infant and maternal behaviours, which mutually change and adapt to fit each other's needs. Key features to reach a successful outcome of the interaction were the maternal retrieving strategy and infants’ Transport Response behaviour. Accepted version

This paper investigates how various factors affect the quality of synthetic speech produced by rules. Using rules to synthesize speech will be an important technique for providing various telecommunication services in future intelligent networks. The quality of synthetic speech is generally measured by subjectively evaluating the speech from the viewpoint of intelligibility, or by comparing it with the quality of other types of synthetic speech. However, the development of a practical speech synthesis method for use in telecommunication networks requires an overall quality evaluation, including intelligibility and naturalness. The quality should be compared with that of natural telephone speech. To establish an overall quality evaluation method, the effects of several factors on the overall quality (expressed by MOS) of speech synthesized by several Japanese text‐to‐speech systems are quantitatively compared with the effects of using additive speech‐correlated white noise as a natural speech material. Exp...