Maternal antibiotics disrupt microbiome, behavior, and temperature regulation in unexposed infant mice.

Maternal antibiotic (ABx) exposure can significantly perturb the transfer of microbiota from mother to offspring, resulting in dysbiosis of potential relevance to neurodevelopmental disorders such as autism spectrum disorder (ASD). Studies in rodent models have found long-term neurobehavioral effects in offspring of ABx-treated dams, but ASD-relevant behavior during the early preweaning period has thus far been neglected. Here, we exposed C57BL/6J mouse dams to ABx (5 mg/ml neomycin, 1.

Oxidative Stress as Cause, Consequence, or Biomarker of Altered Female Reproduction and Development in the Space Environment.

Oxidative stress has been implicated in the pathophysiology of numerous terrestrial disease processes and associated with morbidity following spaceflight. Furthermore, oxidative stress has long been considered a causative agent in adverse reproductive outcomes. The purpose of this review is to summarize the pathogenesis of oxidative stress caused by cosmic radiation and microgravity, review the relationship between oxidative stress and reproductive outcomes in females, and explore what role spaceflight-induced oxidative damage may have on female reproductive and developmental outcomes.

Oxytocin and the warm outer glow: Thermoregulatory deficits cause huddling abnormalities in oxytocin-deficient mouse pups.

Oxytocin is a social and reproductive hormone that also plays critical roles in a range of homeostatic processes, including thermoregulation. Here, we examine the role of oxytocin (OT) as a mediator of brown adipose tissue (BAT) thermogenesis, cold-induced huddling, and thermotaxis in eight-day-old (PD8) OT 'knock out' (OTKO) mouse pups. We tested OTKO and wildtype (WT) pups in single- and mixed-genotype groups of six, exposing these to a period of ambient warmth (~35°C) followed by a period of cold (~21.

Development of behavioral responses to thermal challenges.

Body temperature regulation involves the development of responses to cold and warm challenges. Matching our understanding of the development of body temperature regulation to warm challenges with that of cold challenges will enhance our understanding of the ontogeny of thermoregulation and reveal different adaptive specializations. Warm and cold thermoregulation are important processes, and they include direct thermal effects on offspring, as well as indirect effects on them, such as those imposed by thermally associated alterations of maternal behavior.

Non-nutritive, thermotactile cues induce odor preference in infant mice (Mus musculus).

Mouse pups (Mus musculus) placed on the midline of a mesh floor suspended over an empty area bounded by 2 odor fields, 1 containing homecage bedding and the other clean bedding, preferentially selected the homecage area when tested on postnatal day (PD) 5, 10, or 12. PD5 pups given a choice of homecage bedding versus age-matched bedding from another litter showed no discrimination, whereas PD10/12 pups preferred own home odors. To test whether such home orientation can be shaped by experience, pups were placed for 2 hrs on PDs 8 and 9 with either a lactating dam, a nonlactating foster dam or a warm tube bearing 1 of 2 novel odors.

Behavioral observation differentiates the effects of an intervention to promote sleep in premature infants: a pilot study.

Purpose: Sleep and ongoing cycling of sleep states are required for neurosensory processing, learning, and brain plasticity. Many aspects of neonatal intensive care environments such as handling for routine and invasive procedures, bright lighting, and noise can create stress, disrupt behavior, and interfere with sleep in prematurely born infants. The study empirically investigated whether a 30-minute observation of infant sleep states and behavior could differentiate an intervention to promote sleep in premature infants with feeding difficulties relative to conventional care (standard positioning, standard crib mattress [SP]).

Sex differences in thermogenesis structure behavior and contact within huddles of infant mice.

Brown adipose tissue (BAT) is a thermogenic effector abundant in most mammalian infants. For multiparous species such as rats and mice, the interscapular BAT deposit provides both an emergency "thermal blanket" and a target for nestmates seeking warmth, thereby increasing the cohesiveness of huddling groups. Sex differences in BAT regulation and thermogenesis have been documented in a number of species, including mice (Mus musculus)--with females generally exhibiting relative upregulation of BAT.

The experience of being born: a natural context for learning to suckle.

Understanding the developmental origins of congenital capabilities such as sucking is fundamental knowledge that can contribute to improving the clinical management of early feeding and facilitate the onset of oral ingestion. We describe analyses in rats showing that sensory stimulation in utero and during birth establishes the newborn's sucking responses to maternal cues. We mimicked elements of labor and delivery (viz.

Evolution and development of dual ingestion systems in mammals: notes on a new thesis and its clinical implications.

Traditionally, the development of oral feeding is viewed as a continuous, unitary process in which reflex-dominated sucking behavior gives rise to a more varied and volitional feeding behavior. In contrast, we consider the thesis that the infant develops two separable ingestive systems, one for suckling and one for feeding. First, we apply an evolutionary perspective, recognizing that suckling-feeding is a universal, mammalian developmental sequence.

Group and individual regulation of physiology and behavior: a behavioral, thermographic, and acoustic study of mouse development.

The traditional approach to the study of thermoregulation in young animals focuses on the regulatory capacities of individuals, which, for multiparous species, risks ignoring critical aspects of the early developmental niche. Here, we examined the ontogeny of regulatory behavior in C57BL/6 mice, employing simultaneous behavioral, thermographic, and acoustic measures of groups and individual pups. Litters of mice were placed in a chamber on Postnatal Day (PND) 2, 4, or 8, in which the ambient temperature (T(a)) gradually cycled (over 50 min) from warm (36.

Observe, simplify, titrate, model, and synthesize: a paradigm for analyzing behavior.

Phenomena in behavior and their underlying neural mechanisms are exquisitely complex problems. Infrequently do we reflect on our basic strategies of investigation and analysis, or formally confront the actual challenges of achieving an understanding of the phenomena that inspire research. Philip Teitelbaum is distinct in his elegant approaches to understanding behavioral phenomena and their associated neural processes.

Oxytocin mediates the acquisition of filial, odor-guided huddling for maternally-associated odor in preweanling rats.

The present study was designed to examine possible roles of oxytocin (OT) in the acquisition of a filial huddling preference in preweanling rats. We used a procedure in which a scented, foster mother can induce an odor-guided huddling preference in preweanling pups, following a single, 2-h-long co-habitation (Kojima and Alberts, 2009, 2011). This single, discrete period for preference learning enables us to observe the mother-pup interactions that establish the pups' preferences and to intervene with experimental manipulations.

Warmth from skin-to-skin contact with mother is essential for the acquisition of filial huddling preference in preweanling rats.

During a single, 2-hr session with a scented foster dam, preweanling rat pups form an affiliative attraction to an odor associated with the maternal caregiver, manifest as a huddling preference. To identify maternal stimuli that induce this filial preference, we quantitatively examined behavioral interactions during odor conditioning. Bout duration of skin-to-skin (STS) contact was positively associated with the preference.

Maternal care can rapidly induce an odor-guided huddling preference in rat pups.

Olfactory-guided huddling is learned and expressed by postnatal day (PND) 15, when rat pups huddle preferentially with conspecifics or with targets bearing an odor previously associated with maternal care. Experiment 1 replicated this induction of an odor-guided huddling preference with a truncated regime of conditioning with a scented foster dam. Pups exposed to an odor in association with foster maternal care during five daily 2-hr sessions on PNDs 1-5, 5-9, or 10-14, but not pups merely exposed to the odor, displayed a huddling preference for the conditioned odor, but only when conditioning commenced after PND5.

Orbital spaceflight during pregnancy shapes function of mammalian vestibular system.

Pregnant rats were flown on the NASA Space Shuttle during the early developmental period of their fetuses' vestibular apparatus and onset of vestibular function. The authors report that prenatal spaceflight exposure shapes vestibular-mediated behavior and central morphology. Postflight testing revealed (a) delayed onset of body righting responses, (b) cardiac deceleration (bradycardia) to 70 degrees head-up roll, (c) decreased branching of gravistatic afferent axons, but (d) no change in branching of angular acceleration receptor projections with comparable synaptogenesis of the medial vestibular nucleus in flight relative to control fetuses.

Rat behavioral thermoregulation integrates with nonshivering thermogenesis during postnatal development.

Rat pups are capable of behavioral thermoregulation, both in the nest and on a thermocline, as early as the 1st week of postnatal life, and these pups can also produce heat metabolically without shivering. The rat pup's primary source of nonshivering thermogenesis is the sympathetically mediated metabolism of brown adipose tissue (BAT). BAT is well formed in newborns and functions shortly after birth.

Maternal anesthesia via isoflurane or ether differentially affects pre-and postnatal behavior in rat offspring.

Our understanding of prenatal behavior has been significantly advanced by techniques for direct observation and manipulation of unanesthetized, behaving rodent fetuses with intact umbilical connections to the mother. These techniques involve brief administration of an inhalant anesthesic, enabling spinal transection of the rat or mouse dam, after which procedures can continue with unanesthetized dams and fetuses. Because anesthetics administered to the mother can cross the placental barrier, it is possible that fetuses are anesthetized to varying degrees.

Effects of labor contractions on catecholamine release and breathing frequency in newborn rats.

Plasma catecholamines in newborn rats (0-2 hr old) were analyzed following vaginal birth, cesarean section with simulated labor contractions, or cesarean section without labor contractions. Upon delivery, pups were exposed to key elements of the rat's natural birth process, that is, umbilical cord occlusion, tactile stimulation, and cooling. Only pups exposed to actual or simulated labor showed an immediate rise in norepinephrine and epinephrine.

Huddling by rat pups: ontogeny of individual and group behavior.

A full account of behavioral development in rats must include the ontogeny of both individual and group behavior. Most of our accumulated knowledge, however, pertains to individual ontogenesis. Group behavior and its development are readily seen in the huddling behavior of rat pups.

Housing pregnant mice (Mus musculus) in small groups facilitates the development of odor-based homing in offspring.

Infant mice (Mus musculus) born to dams housed in isolation throughout pregnancy (IsoPreg) begin differentially approaching homenest bedding over clean bedding on Postnatal Day 6. Offspring of dams housed with 2 other potentially pregnant conspecifics (SocPreg) display such homing behavior on Day 4. Earlier onset of homing reflects facilitated olfactory responsiveness in SocPreg pups, rather than qualitative or quantitative differences in IsoPreg versus SocPreg nest odors, body growth, or motoric capabilities.

Development as adaptation: a paradigm for gravitational and space biology.

Adaptation is a central precept of biology; it provides a framework for identifying functional significance. We equate mammalian development with adaptation, by viewing the developmental sequence as a series of adaptations to a stereotyped sequence of habitats. In this way development is adaptation.

The validity and utility of geotaxis in young rodents.

Negative geotaxis, an automatic, reliable, stimulus-bound, orientation and movement directionally against gravitational cues, is often used for behavioral assessments of infant rodents. We summarize historical and contemporary analyses and conclude that negative geotaxis does not exist in infant rats. Infant rodents placed on inclined surfaces (ranging from 15 degrees to 70 degrees in most tests) are posturally unstable and their compensatory responses have been misinterpreted as negative geotaxis.

Positive geotaxis in infant rats (Rattus norvegicus): a natural behavior and a historical correction.

Infant rats (Rattus norvegicus) placed on a shallow incline (2 degrees, 4 degrees, or 8 degrees) oriented and moved downhill within 1 min; that is, they displayed positive geotaxis. Their downhill translocation increased with angle of inclination. A variety of possible behavioral elements (e.