Recovery of memory from infantile amnesia is developmentally constrained

Episodic memories formed during infancy are rapidly forgotten, a phenomenon associated with infantile amnesia, the inability of adults to recall early-life memories. In both rats and mice, infantile memories, although not expressed, are actually stored long term in a latent form. These latent memories can be reinstated later in life by certain behavioral reminders or by artificial reactivations of neuronal ensembles activated at training. Whether the recovery of infantile memories is limited by developmental age, maternal presence, or contingency of stimuli presentation remains to be determined. Here, we show that the return of inhibitory avoidance memory in rats following a behavioral reactivation consisting of an exposure to the context (conditioned stimuli [CS]) and footshock (unconditioned stimuli [US]) given in a temporally unpaired fashion, is evident immediately after US and is limited by the developmental age at which the reactivations are presented; however, it is not influenced by maternal presence or the time interval between training and reactivation. We conclude that one limiting factor for infantile memory reinstatement is developmental age, suggesting that a brain maturation process is necessary to allow the recovery of a “lost” infantile memory.

microRNAs and Gene–Environment Interactions in Autism: Effects of Prenatal Maternal Stress and the SERT Gene on Maternal microRNA Expression

Background: Genetics and environment both are critical in autism spectrum disorder (ASD), but their interaction (G × E) is less understood. Numerous studies have shown higher incidence of stress exposures during pregnancies with children later diagnosed with ASD. However, many stress-exposed mothers have unaffected children. The serotonin transporter (SERT) gene affects stress reactivity. Two independent samples have shown that the association between maternal stress exposure and ASD is greatest with maternal presence of the SERT short (S)-allele (deletion in the promoter region). MicroRNAs play a regulatory role in the serotonergic pathway and in prenatal stress and are therefore potential mechanistic targets in this setting.Design/methods: We profiled microRNA expression in blood from mothers of children with ASD, with known stress exposure during pregnancy. Samples were divided into groups based on SERT genotypes (LL/LS/SS) and prenatal stress level (high/low).Results: Two thousand five hundred mature microRNAs were examined. The ANOVA analysis showed differential expression (DE) of 119 microRNAs; 90 were DE in high- vs. low-stress groups (stress-dependent). Two (miR-1224-5p, miR-331-3p) were recently reported by our group to exhibit stress-dependent expression in rodent brain samples from embryos exposed to prenatal stress. Another, miR-145-5p, is associated with maternal stress. Across SERT genotypes, with high stress exposure, 20 significantly DE microRNAs were detected, five were stress-dependent. These microRNAs may be candidates for stress × SERT genotype interactions. This is remarkable as these changes were from mothers several years after stress-exposed pregnancies.Conclusions: Our study provides evidence for epigenetic alterations in relation to a G × E model (prenatal maternal stress × SERT gene) in ASD.

Housekeeping and the Phantom Ordinary

This chapter shifts focus away from the luminous images of Housekeeping to the lived experiences of traumatic grief those images often veil. The lyrical beauty of Housekeeping offers stylistic reinforcement of a first-person narrative that seeks consolation in immaterial forms. Critical focus on the transfigured ordinary and its aesthetic compensations tends to substantiate rather than interrogate the project of Ruth, focusing on the vibrancy and vitality of the images that she conjures rather than her terrifying expulsion from the everyday. Haunted by memories of maternal presence and incapable of resurrecting her mother, Robinson’s protagonist attempts to write herself out of the everyday world and into the spectral landscape in which her mother continues to exist; rendering her own embodied existence in ghostly terms, Ruth situates herself in a phantom ordinary. Housekeeping, I argue, subtly interrogates Ruth’s substitution of aesthetic images for ordinary presence in a way that anticipates the dramatic collapse of aesthetic consolation in Robinson’s later fiction.

Mother care for procedural pain in infants

A major role of mothers is to protect their infant from harm, including pain. The aim of this chapter is to review the evidence on the effectiveness of maternal strategies that are efficacious in managing procedural pain. These strategies are naturally occurring and have been used for millenia by mothers, but only recently have been systematically studied. Breastfeeding, holding the baby on the bare chest, known as kangaroo mother care, are such strategies. Whilst providing care in this close manner, other components of the mother’s presence may play a role, such as her voice and her odor. Facsimiles of maternal presence such as a recording of mother’s voice and materials containing her odour have been examined as potential strategies to relieve pain in the infant. The question of the potency of pain relieving strategies provided by caregivers, other than the mother, has been addressed to some extent and will be included in this chapter. The mechanisms underlying the pain relieving effects of maternal care, as they are currently understood, will be presented. Finally, pragmatic issues in implementing maternal strategies for decreasing pain will be discussed

Children are important too: juvenile playgroups and maternal childcare in a foraging population, the Agta

Non-maternal carers (allomothers) are hypothesized to lighten the mother's workload, allowing for the specialized human life history including relatively short interbirth intervals and multiple dependent offspring. Here, using in-depth observational data on childcare provided to 78 Agta children (a foraging population in the northern Philippines; aged 0–6 years), we explore whether allomaternal childcare substitutes and decreases maternal childcare. We found that allomother caregiving was associated with reduced maternal childcare, but the substitutive effect varied depending on the source and type of care. Children-only playgroups consistently predicted a decrease in maternal childcare. While grandmothers were rarely available, their presence was negatively associated with maternal presence and childcare, and grandmothers performed similar childcare activities to mothers. These results underscore the importance of allomothering in reducing maternal childcare in the Agta. Our findings suggest that flexibility in childcare sources, including children-only playgroups, may have been the key to human life-history evolution. Overall, our results reinforce the necessity of a broad conceptualization of social support in human childcare. This article is part of the theme issue ‘Multidisciplinary perspectives on social support and maternal–child health’.

Early acquisition of threat conditioning in a selectively-bred anxiety-like rat phenotype: regulation by maternal presence and FGF2

Temperament is an innate, stable predisposition towards particular emotional and behavioral responses. In humans, certain temperaments are associated with a heightened risk of developing anxiety later in life. Non-human animals, including rodents, also exhibit innate, stable dispositions; these are referred to as behavioral phenotypes. The interaction between behavioral phenotype and early life adverse events is critical for the development of maladaptive anxiety. Rodent studies of typically developing animals have identified a number of mechanisms that protect against aversive experiences in early life. One such mechanism is an early life quiescence of threat learning, which protects against the effects of stress and facilitates safety and attachment learning. However, little is known about the factors that alleviate the effects of early life aversive events on phenotypes vulnerable to pathological anxiety. Here, we examined threat learning and the stress response in selectively-bred infant rats that show an anxiety-like phenotype relative to typically developing animals. We investigated the potential roles of maternal presence and the anxiolytic neurotrophic factor fibroblast growth factor 2 (FGF2) in regulating threat learning and the stress response in infant anxiety-like phenotype animals. We observed that rats selectively-bred for anxiety-like behaviors could acquire conditioned freezing earlier in life than typically developing animals. FGF2 administration on postnatal day 1 (PND 1) and maternal presence during threat conditioning were both capable of suppressing this early emergence of conditioned freezing. However, neither FGF2 nor maternal presence during threat conditioning were associated with reduced corticosterone levels during threat conditioning. Our results suggest that although an anxiety-like phenotype may be associated with early threat learning, environmental factors (such as maternal presence) and pharmacological intervention (such as modulation of the FGF2 system) may be capable of counteracting that early aversive learning. Interventions in vulnerable infants may thus decrease the impact of aversive events.

Associations Between Single-Family Room Care and Breastfeeding Rates in Preterm Infants

Background Hospitalization in neonatal intensive care units with a single-family room design enables continuous maternal presence, but less is known regarding the association with milk production and breastfeeding. Research aim To compare maternal milk production, breastfeeding self-efficacy, the extent to which infants received mother’s milk, and rate of direct breastfeeding in a single-family room to an open bay neonatal intensive care unit. Methods A longitudinal, prospective observational study comparing 77 infants born at 28– 32° weeks gestational age and their 66 mothers ( n = 35 infants of n = 30 mothers in single family room and n = 42 infants of n = 36 mothers in open bay). Comparisons were made on milk volume produced, the extent to which infants were fed mother’s milk, and rate of direct breastfeeding from birth to 4 months’ corrected infant age. Breastfeeding self-efficacy was compared across mothers who directly breastfed at discharge ( n = 45). Results First expression (6 hr vs. 30 hr, p < .001) and first attempt at breastfeeding (48 hr vs. 109 hr, p < .001) occurred significantly earlier, infants were fed a greater amount of mother’s milk ( p < .04), and significantly more infants having single-family room care were exclusively directly breastfed from discharge until 4 months’ corrected age; OR 6.8 (95% CI [2.4, 19.1]). Volumes of milk produced and breastfeeding self-efficacy did not differ significantly between participants in either units. Conclusion To increase the extent to which infants are fed mother’s own milk and are exclusively directly breastfed, the design of neonatal intensive care units should facilitate continuous maternal presence and privacy for the mother–infant dyad.

The Hammock as a Therapeutic Alternative at The Neonatal Intensive Care Unit

Background: Among the therapeutic alternatives complementary to humanized care, there is the vestibular stimulation. Provided by the gentle swing in a hammock, it simulates the containment and maternal movements found in the intrauterine environment and is considered a safe method that reduces stress levels in very low birthweight premature newborn (PTNB). Objective: To observe the time of hospitalization and the discharge weight of the PTNB that passed through the positioning in the hammock and kangaroo mother care. Methods: A quasi-experimental study involving two university hospitals including PTNB. The PTNB were allocated into two groups: Kangaroo Mother Care (KMC) composed by PTNB selected according to the maternal presence and vestibular stimulation (VS) composed by PTNB whose maternal presence was not possible. The KMC were kept in skin-to-skin contact with the mother. The VS were positioned in dorsal decubitus in a hammock of cotton adapted within the incubator. The time of hospitalization and weight monitoring were recorded daily by the nursing team in a collection form. Results: From the 40 PTNB included in this study, 47.5% were female and 40% had normal birth, 20 of them were allocated in the VS group and 20 in the KMC group. The time of hospitalization were not different between the groups (p=0.12), but the discharge weight were higher in the VS group (p<0.05). Conclusion: The data indicate that the hospitalization time is similar between the PTNB who received KMC and VS, and that the discharge weight is higher for the group that received the VS.