scholarly journals The effects of maternal separation on behaviours under social-housing environments in adult male C57BL/6 mice

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nozomi Endo ◽  
Manabu Makinodan ◽  
Takayo Mannari-Sasagawa ◽  
Noriko Horii-Hayashi ◽  
Nami Somayama ◽  
...  
Keyword(s):  
Psychiatric Disorders ◽  
Adult Male ◽  
Life Stress ◽  
Early Life ◽  
Maternal Separation ◽  
Early Life Stress ◽  
Group Housing ◽  
Housing Conditions ◽  
Post Traumatic Stress ◽  
Post Traumatic

AbstractAdverse experience in early life can affect the formation of neuronal circuits during postnatal development and exert long-lasting influences on neural functions that can lead to the development of a variety of psychiatric disorders including depression, anxiety disorders, and post-traumatic stress disorder. Many studies have demonstrated that daily repeated maternal separation, an animal model of early-life stress, can induce impairments in emotional behaviours and cognitive function during adolescence and adulthood. However, the behavioural phenotypes of maternally separated mice under long-term group-housing conditions are largely unknown. In this study, we applied our newly developed assay system to investigate the effects of maternal separation on behaviours under group-housing conditions during four days of continuous observations. Using our system, we found that repeated maternal separation resulted in inappropriate social distance from cagemates, altered approach preferences to others, and induced a lower rank in the time spent on the running wheel under group-housing conditions in adult male mice. Focussing on these behavioural abnormalities that appear in an environment with a social context will be important insights to understand the pathogenesis of psychiatric disorders.

scholarly journals Impact of mothers’ past experience and early-life stress on aggression and cognition in adult male mice

2018 ◽  
Author(s):  
V. Reshetnikov ◽  
Yu. Ryabushkina ◽  
N. Bondar
Keyword(s):  
Locomotor Activity ◽  
Adult Male ◽  
Life Stress ◽  
Early Life ◽  
Maternal Separation ◽  
Life Experience ◽  
Early Life Stress ◽  
Male Mice ◽  
Female Mice ◽  
Stressful Experience

AbstractEarly life is an important period for brain development and behavioral programming. Both reduced maternal care and stress in early life are risk factors for various psychiatric disorders. Here, we hypothesized that females’ stressful experience in their early life can lead to a disruption of mother-offspring interactions toward their own progeny. The objective of this study is to assess the effects of mothers’ past stressful experience, early-life stress alone or both on behavior in adult male mice. In this study, female mice were allowed to raise their pups either without exposure to stress (normal rearing condition, NC) or with exposure to maternal separation (3h/day, maternal separation, MS) on postnatal days 2–14. Adult F1 female mice who had experienced MS (stressed mothers, SM) or had been reared normally (undisturbed mothers, UM) were used for generating F2 offspring to be or not to be further exposed to early-life stress. We assessed anxiety-like behavior, exploratory activity, locomotor activity, aggression and cognition in four groups of adult F2 males (UM+NC, UM+MS, SM+NC, SM+MS). We found that SM+MS males become more aggressive if agonistic contact is long enough, suggesting a change in their social coping strategy. Moreover, these aggressive males tended to improve longterm spatial memory. Aggressive SM+NC males, in contrast, showed learning impairments. We did not find any significant differences in anxiety-like behavior or exploratory and locomotor activity. Overall, our findings suggest that mothers’ early-life experience may have important implications for the adult behavior of their offspring.

scholarly journals Functional Alterations and Cerebral Variations in Humans Exposed to Early Life Stress

2021 ◽  
Vol 8 ◽  
Author(s):  
Carlos A. González-Acosta ◽  
Christian A. Rojas-Cerón ◽  
Efraín Buriticá
Keyword(s):  
Psychiatric Disorders ◽  
Life Stress ◽  
Early Life ◽  
Early Life Stress ◽  
Anterior Cingulate ◽  
Brain Anatomy ◽  
Physical And Mental Health ◽  
Post Traumatic Stress ◽  
Early Stress ◽  
The Impact

Early life stress can be caused by acute or chronic exposure to childhood events, such as emotional, physical, sexual abuse, and neglect. Early stress is associated with subsequent alterations in physical and mental health, which can extend into adolescence, adulthood, and even old age. The effects of early stress exposure include alterations in cognitive, neuropsychological, and behavioral functions, and can even lead to the development of psychiatric disorders and changes in brain anatomy. The present manuscript provides a review of the main findings on these effects reported in the scientific literature in recent decades. Early life stress is associated with the presence of psychiatric disorders, mainly mood disorders such as depression and risk of suicide, as well as with the presence of post-traumatic stress disorder. At the neuropsychological level, the involvement of different mental processes such as executive functions, abstract reasoning, certain memory modalities, and poor school-skill performance has been reported. In addition, we identified reports of alterations of different subdomains of each of these processes. Regarding neuroanatomical effects, the involvement of cortical regions, subcortical nuclei, and the subcortical white matter has been documented. Among the telencephalic regions most affected and studied are the prefrontal cortex, the hippocampus, the amygdala, and the anterior cingulate cortex. Understanding the impact of early life stress on postnatal brain development is very important for the orientation of therapeutic intervention programs and could help in the formulation and implementation of preventive measures as well as in the reorientation of research targets.

scholarly journals Altered hypothalamic DNA methylation and stress-induced hyperactivity in a novel model of early life stress

2020 ◽  
Author(s):  
Eamon Fitzgerald ◽  
Matthew C Sinton ◽  
Sara Wernig-Zorc ◽  
Nicholas M Morton ◽  
Megan C Holmes ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Preterm Birth ◽  
Psychiatric Disorders ◽  
Open Field ◽  
Life Stress ◽  
Early Life ◽  
Maternal Separation ◽  
Early Life Stress ◽  
Mediated Effects ◽  
Novel Model

AbstractEarly life stress during childhood is associated with a number of psychiatric disorders that manifest across the life course. Preterm birth is a profound stressor, and an important cause of cognitive impairment, as well as neurodevelopmental and psychiatric disorders. However, the mechanisms that link events during the early neonatal period with later functional problems are poorly understood. We developed a novel mouse model of early life stress (modified maternal separation; MMS) with specific relevance to preterm birth (PTB) and hypothesised it would affect the hypothalamic transcriptome and DNA methylome and impact on behaviour in adulthood. MMS consisted of repeatedly stimulating pups for 1.5 hours/day, whilst separated from their mother, from postnatal day (P)4-6. 3’ RNA sequencing and DNA methylation immunoprecipitation (meDIP) sequencing was performed on the hypothalamus at P6. Behaviour was assessed with the elevated plus and open field mazes, and in-cage monitoring at 3-4 months of age. Although MMS was only associated with subtle changes in gene expression there were widespread alterations in DNA methylation. Notably, differentially methylated regions were enriched for synapse-associated loci. MMS also resulted in hyperactivity in the elevated plus and open field mazes, but in-cage monitoring revealed that this was not representative of habitual hyperactivity. In conclusion we describe a novel model of early life stress with relevance to PTB, with marked effects on DNA methylation in the hypothalamus and with stress-specific hyperactivity in young adulthood. We suggest that these results have implications for the understanding of early life stress mediated effects on brain development.

scholarly journals Early-Life Stress Modulates Gut Microbiota and Peripheral and Central Inflammation in a Sex-Dependent Manner

2021 ◽  
Vol 22 (4) ◽  
pp. 1899 ◽  
Author(s):  
Hae Jeong Park ◽  
Sang A. Kim ◽  
Won Sub Kang ◽  
Jong Woo Kim
Keyword(s):  
Gut Microbiota ◽  
Relative Abundance ◽  
Life Stress ◽  
Early Life ◽  
Maternal Separation ◽  
Early Life Stress ◽  
Female Rats ◽  
Rrna Gene ◽  
Dependent Manner ◽  
Male And Female Rats

Recent studies have reported that changes in gut microbiota composition could induce neuropsychiatric problems. In this study, we investigated alterations in gut microbiota induced by early-life stress (ELS) in rats subjected to maternal separation (MS; 6 h a day, postnatal days (PNDs) 1–21), along with changes in inflammatory cytokines and tryptophan-kynurenine (TRP-KYN) metabolism, and assessed the differences between sexes. High-throughput sequencing of the bacterial 16S rRNA gene showed that the relative abundance of the Bacteroides genus was increased and that of the Lachnospiraceae family was decreased in the feces of MS rats of both sexes (PND 56). By comparison, MS increased the relative abundance of the Streptococcus genus and decreased that of the Staphylococcus genus only in males, whereas the abundance of the Sporobacter genus was enhanced and that of the Mucispirillum genus was reduced by MS only in females. In addition, the levels of proinflammatory cytokines were increased in the colons (IFN-γ and IL-6) and sera (IL-1β) of the male MS rats, together with the elevation of the KYN/TRP ratio in the sera, but not in females. In the hippocampus, MS elevated the level of IL-1β and the KYN/TRP ratio in both male and female rats. These results indicate that MS induces peripheral and central inflammation and TRP-KYN metabolism in a sex-dependent manner, together with sex-specific changes in gut microbes.

scholarly journals Sexual dimorphic role of the glucocorticoid receptor in chronic muscle pain produced by early-life stress

2021 ◽  
Vol 17 ◽  
pp. 174480692110113
Author(s):  
Paul G Green ◽  
Pedro Alvarez ◽  
Jon D Levine
Keyword(s):  
Glucocorticoid Receptor ◽  
Adult Male ◽  
Life Stress ◽  
Early Life ◽  
Glucocorticoid Receptors ◽  
Early Life Stress ◽  
Nociceptive Threshold ◽  
Male And Female ◽  
Mechanical Nociceptive Threshold

Fibromyalgia and other chronic musculoskeletal pain syndromes are associated with stressful early life events, which can produce a persistent dysregulation in the hypothalamic-pituitary adrenal (HPA) stress axis function, associated with elevated plasm levels of corticosterone in adults. To determine the contribution of the HPA axis to persistent muscle hyperalgesia in adult rats that had experienced neonatal limited bedding (NLB), a form of early-life stress, we evaluated the role of glucocorticoid receptors on muscle nociceptors in adult NLB rats. In adult male and female NLB rats, mechanical nociceptive threshold in skeletal muscle was significantly lower than in adult control (neonatal standard bedding) rats. Furthermore, adult males and females that received exogenous corticosterone (via dams’ milk) during postnatal days 2–9, displayed a similar lowered mechanical nociceptive threshold. To test the hypothesis that persistent glucocorticoid receptor signaling in the adult contributes to muscle hyperalgesia in NLB rats, nociceptor expression of glucocorticoid receptor (GR) was attenuated by spinal intrathecal administration of an oligodeoxynucleotide (ODN) antisense to GR mRNA. In adult NLB rats, GR antisense markedly attenuated muscle hyperalgesia in males, but not in females. These findings indicate that increased corticosterone levels during a critical developmental period (postnatal days 2–9) produced by NLB stress induces chronic mechanical hyperalgesia in male and female rats that persists in adulthood, and that this chronic muscle hyperalgesia is mediated, at least in part, by persistent stimulation of glucocorticoid receptors on sensory neurons, in the adult male, but not female rat.

scholarly journals Maternal Separation as Early-Life Stress Causes Enhanced Allergic Airway Responses by Inhibiting Respiratory Tolerance in Mice

2018 ◽  
Vol 246 (3) ◽  
pp. 155-165 ◽  
Author(s):  
Ryusuke Ouchi ◽  
Tasuku Kawano ◽  
Hitomi Yoshida ◽  
Masato Ishii ◽  
Tomomitsu Miyasaka ◽  
...  
Keyword(s):  
Life Stress ◽  
Early Life ◽  
Maternal Separation ◽  
Early Life Stress ◽  
Airway Responses

scholarly journals Maternal separation in rodents: a journey from gut to brain and nutritional perspectives

2019 ◽  
Vol 79 (1) ◽  
pp. 113-132 ◽  
Author(s):  
Marion Rincel ◽  
Muriel Darnaudéry
Keyword(s):  
Life Stress ◽  
Early Life ◽  
Maternal Separation ◽  
Human Subjects ◽  
Early Life Stress ◽  
Long Term Effects ◽  
Early Life Adversity ◽  
Critical Window ◽  
Beneficial Impact ◽  
The Impact

The developmental period constitutes a critical window of sensitivity to stress. Indeed, early-life adversity increases the risk to develop psychiatric diseases, but also gastrointestinal disorders such as the irritable bowel syndrome at adulthood. In the past decade, there has been huge interest in the gut–brain axis, especially as regards stress-related emotional behaviours. Animal models of early-life adversity, in particular, maternal separation (MS) in rodents, demonstrate lasting deleterious effects on both the gut and the brain. Here, we review the effects of MS on both systems with a focus on stress-related behaviours. In addition, we discuss more recent findings showing the impact of gut-directed interventions, including nutrition with pre- and probiotics, illustrating the role played by gut microbiota in mediating the long-term effects of MS. Overall, preclinical studies suggest that nutritional approaches with pro- and prebiotics may constitute safe and efficient strategies to attenuate the effects of early-life stress on the gut–brain axis. Further research is required to understand the complex mechanisms underlying gut–brain interaction dysfunctions after early-life stress as well as to determine the beneficial impact of gut-directed strategies in a context of early-life adversity in human subjects.

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