Prenatal malnutrition and sleep states in adult rats: effects of restraint stress

Third-Trimester Maternal Dietary Patterns Are Associated with Sleep Health among Adolescent Offspring in a Mexico City Cohort

BACKGROUND

Maternal diet during gestation has been linked to infant sleep; whether associations persist through adolescence is unknown.

OBJECTIVES

We explored associations between trimester-specific maternal diet patterns and measures of sleep health among adolescent offspring in a Mexico City birth cohort.

METHODS

Data from 310 mother-adolescent dyads were analyzed. Maternal diet patterns were identified by principal component analysis derived from FFQs collected during each trimester of pregnancy. Sleep duration, midpoint, and fragmentation were obtained from 7-d actigraphy data when adolescents were between 12 and 20 y old. Unstratified and sex-stratified association analyses were conducted using linear regression models, adjusted for potential confounders.

RESULTS

Mean ± SD age of offspring was 15.1 ± 1.9 y, and 52.3% of the sample was female. Three diet patterns were identified during each trimester of pregnancy: the Prudent Diet (PD), high in lean proteins and vegetables; the Transitioning Mexican Diet (TMD), high in westernized foods; and the High Meat & Fat Diet (HMFD), high in meats and fat products. Mean ± SD sleep duration was 8.5 ± 1.5 h/night. Most associations were found in the third trimester. Specifically, PD maternal adherence was associated with shorter sleep duration among offspring (-0.57 h; 95% CI: -0.98, -0.16 h, in the highest tertile compared with the lowest) and earlier sleep midpoint among females (-0.77 h; 95% CI: -1.3, -0.26 h). Adherence to the HMFD and TMD was nonlinearly associated with less fragmented sleep, with the latter only evident among females.

CONCLUSIONS

Findings indicate that maternal dietary patterns, especially during the third trimester of pregnancy, may have long-term impacts on offspring sleep.

The enduring effect of prenatal protein malnutrition on brain anatomy, physiology and behavior

There is increasing evidence that the maternal environment exerts enduring influences on the fetal brain. In response to certain environmental stimuli such as reduced protein content, the fetus changes the course of its brain development, which leads to specific and programed changes in brain anatomy and physiology. These alterations produce a brain with a fundamentally altered organization, which then translates to alterations in adult cognitive function. The effects on brain and behavior may be linked, such that a prenatal stimulus relays a signal to alter brain development and encourage the selection and development of brain circuits and behaviors that would be beneficial for the environment in which the animal was anticipated to emerge. At the same time, the signal would deselect behaviors unlikely to be adaptive. We draw on evidence from rodent models to suggest that the brain that develops after a reduction in protein during the prenatal phase is not uniformly dysfunctional, but simply different. This perspective has implications for the role of prenatal factors in the production and expression of behavior, and may account for the elevation of risk factors for neurological and psychiatric illnesses.

Childhood malnutrition and maltreatment are linked with personality disorder symptoms in adulthood: Results from a Barbados lifespan cohort

Both childhood malnutrition and maltreatment are associated with mental health problems that can persist into adulthood. Previously we reported that in Barbados, those with a history of infant malnutrition were more likely to report having experienced childhood maltreatment. Few studies, however, address the long-term outcomes of those who have been exposed to both. We assessed the unique and combined associations of a history of early malnutrition and childhood maltreatment with personality pathology in mid-adulthood in participants of the 47-year longitudinal Barbados Nutrition Study. We used the Structured Clinical Interview for DSM-IV-TR Axis II Personality Disorders Personality Questionnaire (SCID-II-PQ) and NEO Personality Inventory-Revised derived Five-Factor Model (NEO PI-R FFM) personality disorder (PD) scores to assess personality pathology, the Childhood Trauma Questionnaire-Short Form (CTQ-SF) to assess childhood maltreatment, and clinical documentation of malnutrition in infancy. We tested the associations of malnutrition and maltreatment with PD scores using linear regression models, unadjusted and adjusted for other childhood adversities. We found increased scores for paranoid, schizoid, avoidant, and dependent PDs among those who had been malnourished and increased scores for paranoid, schizoid, schizotypal, and avoidant PDs among those with higher childhood maltreatment scores. Overall, those exposed to both adversities had even greater PD scores.

Chronic Maternal Low-Protein Diet in Mice Affects Anxiety, Night-Time Energy Expenditure and Sleep Patterns, but Not Circadian Rhythm in Male Offspring

Offspring of murine dams chronically fed a protein-restricted diet have an increased risk for metabolic and neurobehavioral disorders. Previously we showed that adult offspring, developmentally exposed to a chronic maternal low-protein (MLP) diet, had lower body and hind-leg muscle weights and decreased liver enzyme serum levels. We conducted energy expenditure, neurobehavioral and circadian rhythm assays in male offspring to examine mechanisms for the body-weight phenotype and assess neurodevelopmental implications of MLP exposure. C57BL/6J dams were fed a protein restricted (8%protein, MLP) or a control protein (20% protein, C) diet from four weeks before mating until weaning of offspring. Male offspring were weaned to standard rodent diet (20% protein) and single-housed until 8–12 weeks of age. We examined body composition, food intake, energy expenditure, spontaneous rearing activity and sleep patterns and performed behavioral assays for anxiety (open field activity, elevated plus maze [EPM], light/dark exploration), depression (tail suspension and forced swim test), sociability (three-chamber), repetitive (marble burying), learning and memory (fear conditioning), and circadian behavior (wheel-running activity during light-dark and constant dark cycles). We also measured circadian gene expression in hypothalamus and liver at different Zeitgeber times (ZT). Male offspring from separate MLP exposed dams had significantly greater body fat (P = 0.03), less energy expenditure (P = 0.004), less rearing activity (P = 0.04) and a greater number of night-time rest/sleep bouts (P = 0.03) compared to control. MLP offspring displayed greater anxiety-like behavior in the EPM (P<0.01) but had no learning and memory deficit in fear-conditioning assay (P = 0.02). There was an effect of time on Per1, Per 2 and Clock circadian gene expression in the hypothalamus but not on circadian behavior. Thus, transplacental and early developmental exposure of dams to chronic MLP reduces food intake and energy expenditure, increases anxiety like behavior and disturbs sleep patterns but not circadian rhythm in adult male offspring.

Protein undernutrition during development and oxidative impairment in the central nervous system (CNS): potential factors in the occurrence of metabolic syndrome and CNS disease

Mitochondria play a regulatory role in several essential cell processes including cell metabolism, calcium balance and cell viability. In recent years, it has been postulated that mitochondria participate in the pathogenesis of a number of chronic diseases, including central nervous system disorders. Thus, the concept of mitochondrial function now extends far beyond the common view of this organelle as the ‘powerhouse’ of the cell to a new appreciation of the mitochondrion as a transducer of early metabolic insult into chronic disease in later life. In this review, we have attempted to describe some of the associations between nutritional status and mitochondrial function (and dysfunction) during embryonic development with the occurrence of neural oxidative imbalance and neurogenic disease in adulthood.

Effects of early protein malnutrition and environmental stimulation on behavioral and biochemical parameters in rats submitted to the elevated plus-maze test

The objective of this study was to compare the effects of the tactile/handling stimulation (H) and environmental enrichment (EE) in well-nourished (C - 16% of protein) and malnourished (M - 6% of protein) rats tested in the elevated plus-maze (EPM) at 36 and 37 days of age. The results showed higher exploration of the open arms in the EPM in M as compared with C animals, as well as lower index of risk assessment behaviors, and EE, but not H, reversed the alterations produced by malnutrition in the EPM. Biochemical analysis showed higher levels of corticosterone in M when compared with C rats. The non-stimulated animals presented higher levels of polyamines in the hippocampus when compared with the stimulated ones in both diet conditions. It is suggested that both the lower anxiety levels and the lower risk-assessment behaviors in the EPM, as well as the higher levels of corticosterone, can be due to alterations in the activity of the hypothalamic-pituitary-adrenal axis as the result of early protein malnutrition.

Prenatal origins of poor sleep in children

STUDY OBJECTIVES

We examined whether small body size at birth and prenatal tobacco or alcohol exposure predict poor sleep and more sleep disturbances in children.

DESIGN

An epidemiologic cohort study of 289 eight-year-old children born at term.

MEASUREMENTS AND RESULTS

Sleep duration and efficiency were measured by actigraphy for 7 consecutive nights (mean = 7.1, SD = 1.2). We used both continuous measures of poor sleep and binary variables of short sleep and low sleep efficiency ( < or = 10th percentiles). Parents completed the Sleep Disturbance Scale for Children. Lower birth weight and shorter length at birth were associated with lower sleep efficiency. For every 1-SD decrease in weight and length at birth, the odds for low sleep efficiency increased by 1.7 fold (95% confidence interval [CI]: 1.1 to 2.7) and 2.2 fold (95% CI: 1.3 to 3.7), respectively. For every 1-SD decrease in ponderal index at birth, the risk of parent-reported sleep disorders increased by 1.4 fold (95% CI: 1.0 to 2.0). Moreover, children exposed prenatally to alcohol had a 2.9-fold (95% CI: 1.1 to 7.6) and 3.6-fold (95% CI: 1.3 to 10.0) increased risk for having short sleep and low sleep efficiency, respectively. The associations were not confounded by sex, gestational length, prenatal and perinatal complications, body mass index at 8 years, asthma, allergies, or parental socioeconomic status.

CONCLUSIONS

Poor sleep in children may have prenatal origins. Possible mechanisms include alcohol consumption during pregnancy and other conditions associated with small body size at birth.

Maternal reports of sleep in 6-18 month-old infants from Nepal and Zanzibar: association with iron deficiency anemia and stunting

BACKGROUND

Infants with iron deficiency anemia (IDA) and stunting explore and interact less with their environment. They may also be fatigued more often, suggesting their sleep may be affected. It is unclear whether fatigue in these infants is due to poor nighttime sleep or if it is compensated for with frequent naps or longer sleep.

AIMS

In 2 studies from Pemba Island, Zanzibar and 1 from Nepal we investigated the relationship between IDA, stunting, and maternal reports of sleep in 6-18 mo old infants.

METHODS

Parents reported on the number and duration of naps, hours of nighttime sleep, and frequency of night waking. Anemia was defined as Hb<10 g/dL, iron deficiency as zinc protoporphyrin (ZPP > or = 90 micromol/mol heme), stunting as HAZ<-2 SD, and IDA as Hb<10 g/dL and ZPP > or = 90 micromol/mol heme.

RESULTS

The prevalence of IDA and stunting was 34-84% and 22-37%, respectively. Most infants napped during the day and took approximately 1.5 naps (mean nap duration 1.4-1.7 h). Mean nighttime sleep duration was 8.3-9.7 h and infants awoke 2.1-2.5 times per night. Both IDA and stunting were associated with differences in reported sleep characterized by shorter night sleep duration and higher frequency of night waking; stunting was also related to shorter nap duration.

CONCLUSIONS

We found reduced sleep duration and increased night waking among infants with IDA and stunting. Because sleep plays an essential role in infant development, our findings indicate a clear need for further research into these relationships.

Stress-induced changes in extracellular dopamine and serotonin in the medial prefrontal cortex and dorsal hippocampus of prenatally malnourished rats

Prenatal protein malnutrition continues to be a significant problem in the world today. Exposure to prenatal protein malnutrition increases the risk of a number of neuropsychiatric disorders in adulthood including depression, schizophrenia and attentional deficit disorder. In the present experiment, we have examined the effects of stress on extracellular serotonin (5-HT) and dopamine in the medial prefrontal cortex and dorsal hippocampus of rats exposed in utero to protein malnutrition. The medial prefrontal cortex and dorsal hippocampus were chosen as two limbic forebrain regions involved in learning and memory, attention and the stress response. Extracellular 5-HT and dopamine were determined in the medial prefrontal cortex and dorsal hippocampus of adult male Sprague-Dawley rats using dual probe in vivo microdialysis. Basal extracellular 5-HT did not differ between malnourished and well-nourished controls in either the medial prefrontal cortex or the dorsal hippocampus. Basal extracellular dopamine was significantly decreased in the medial prefrontal cortex of malnourished animals. Restraint stress (20 m) produced a significant rise in extracellular dopamine in the medial prefrontal cortex of well-nourished rats but did not alter release in malnourished rats. In malnourished rats, stress produced an increase in 5-HT in the hippocampus, whereas stress produced a decrease in 5-HT in the hippocampus of well-nourished rats. These data demonstrate that prenatal protein malnutrition alters dopaminergic neurotransmission in the medial prefrontal cortex as well as alters the dopaminergic and serotonergic response to stress. These changes may provide part of the bases for alterations in malnourished animals' response to stress.

Prenatal malnutrition alters diazepam-mediated suppression of ultrasonic vocalizations in an age dependent manner

The sensitivity of prenatally malnourished rats to the ultrasonic vocalization (USV) suppressant effect of diazepam (a non-specific benzodiazepine (BZ) receptor agonist) was investigated. Male offspring of dams provided with a protein deficient diet (6% casein) for 5 weeks prior to mating and throughout pregnancy were compared to the offspring of mothers provided with a diet of adequate protein content (25% casein). At postnatal day 7 or 11, pups were injected with vehicle or one of five doses of DZ (0.03, 0.1, 0.3, 1 or 3mg/kg) 30 min after removal from their dam. Thirty minutes later they were subjected to 2 min of cooling on a 20 degrees C surface and their USVs were quantified. DZ dose-dependently suppressed USV at both ages. At P7, the USV suppressant effect of DZ was the same for both groups. However, by P11 the prenatally malnourished rats showed significantly greater suppression of USV by 0.03 and 0.1mg/kg DZ than well-nourished controls. These differences were not related to degree of temperature loss or body weight. Thus, differential sensitivity to BZ receptor agonists develops in the second postnatal week in prenatally malnourished rats. This reflects either an altered program of development of the GABAergic system, or adaptive, compensatory changes in the GABAergic system in response to more extensive functional disturbances in the developing brain.