The influence of neonatal nutrition on behavioral development: a critical appraisal

How Social Experience and Environment Impacts Behavioural Plasticity in Drosophila

An organism's behaviour is influenced by its social environment. Experiences such as social isolation or crowding may have profound short or long-term effects on an individual's behaviour. The composition of the social environment also depends on the genetics and previous experiences of the individuals present, leading to additional potential outcomes from each social interaction. In this article, we review selected literature related to the social environment of the model organism Drosophila melanogaster, and how Drosophila respond to variation in their social experiences throughout their lifetimes. We focus on the effects of social environment on behavioural phenotypes such as courtship, aggression, and group dynamics, as well as other phenotypes such as development and physiology. The consequences of phenotypic plasticity due to social environment are discussed with respect to the ecology and evolution of Drosophila. We also relate these studies to laboratory research practices involving Drosophila and other animals.

mRNA profile provides novel insights into stress adaptation in mud crab megalopa, Scylla paramamosain after salinity stress

Background

Mud crab, Scylla paramamosain, a euryhaline crustacean species, mainly inhabits the Indo-Western Pacific region. Wild mud crab spawn in high-salt condition and the salinity reduced with the growth of the hatching larvae. When the larvae grow up to megalopa, they migrate back to estuaries and coasts in virtue of the flood tide, settle and recruit adult habitats and metamorphose into the crablet stage. Adult crab can even survive in a wide salinity of 0–35 ppt. To investigate the mRNA profile after salinity stress, S. paramamosain megalopa were exposed to different salinity seawater (low, 14 ppt; control, 25 ppt; high, 39 ppt).

Results

Firstly, from the expression profiles of Na+/K+/2Cl- cotransporter, chloride channel protein 2, and ABC transporter, it turned out that the 24 h might be the most influenced duration in the short-term stress. We collected megalopa under different salinity for 24 h and then submitted to mRNA profiling. Totally, 57.87 Gb Clean Data were obtained. The comparative genomic analysis detected 342 differentially expressed genes (DEGs). The most significantly DEGs include gamma-butyrobetaine dioxygenase-like, facilitated trehalose transporter Tret1, sodium/potassium-transporting ATPase subunit alpha, rhodanese 1-like protein, etc. And the significantly enriched pathways were lysine degradation, choline metabolism in cancer, phospholipase D signaling pathway, Fc gamma R-mediated phagocytosis, and sphingolipid signaling pathway. The results indicate that in the short-term salinity stress, the megalopa might regulate some mechanism such as metabolism, immunity responses, osmoregulation to adapt to the alteration of the environment.

Conclusions

This study represents the first genome-wide transcriptome analysis of S. paramamosain megalopa for studying its stress adaption mechanisms under different salinity. The results reveal numbers of genes modified by salinity stress and some important pathways, which will provide valuable resources for discovering the molecular basis of salinity stress adaptation of S. paramamosain larvae and further boost the understanding of the potential molecular mechanisms of salinity stress adaptation for crustacean species.

Red-eared slider hatchlings (Trachemys scripta) show a seasonal shift in behavioral types

Correlated and repeatable patterns of behavior, termed behavioral types, can affect individual fitness. The most advantageous behavioral type may differ across predictable environments (e.g., seasonally), and maternally mediated effects may match hatchling behavior to the environment. We measured righting response, an indicator of behavioral type, of juvenile red-eared slider turtles (Trachemys scripta) emerging from early and late season clutches to understand if the production of behavioral types differs across the nesting season. There was a significant effect of season, with early season hatchlings righting more quickly than late season hatchlings, and we explored two potential underlying mechanisms, maternal estrogens and maternal investment (e.g., yolk allocation). We dosed early season eggs with an estrogen mixture to mimic late season eggs and assayed hatchling righting response, but found no significant effect of this maternal effect. We assessed maternal investment by measuring egg, hatchling, and residual yolk masses. We found a seasonal pattern in yolk allocation, where early season eggs have more yolk than late season eggs. Early season hatchlings used more yolk for growth rather than maintenance of existing tissues, resulting in larger hatchlings. Interestingly, across both seasons, hatchlings that received less maternal yolk appeared to be more efficient at converting yolk to tissue, but we found no direct correlation with righting behavior. We demonstrate that the prevalence of behavioral types varies across the nesting season, creating correlated suites of seasonal phenotypes in turtle hatchlings, but it appears that neither maternal estrogens or investment in yolk directly underlie this shift in behavior.

Maternal long chain polyunsaturated fatty acid status and pregnancy complications

Maternal nutrition plays a crucial role in influencing fetal growth and birth outcome. Any nutritional insult starting several weeks before pregnancy and during critical periods of gestation is known to influence fetal development and increase the risk for diseases during later life. Literature suggests that chronic adult diseases may have their origin during early life - a concept referred to as Developmental Origins of Health and Disease (DOHaD) which states that adverse exposures early in life "program" risks for later chronic disorders. Long chain polyunsaturated fatty acids (LCPUFA), mainly omega-6 and omega-3 fatty acids are known to have an effect on fetal programming. The placental supply of optimal levels of LCPUFA to the fetus during early life is extremely important for the normal growth and development of both placenta and fetus. Any alteration in placental development will result in adverse pregnancy outcome such as gestational diabetes mellitus (GDM), preeclampsia, and intrauterine growth restriction (IUGR). A disturbed materno-fetal LCPUFA supply is known to be linked with each of these pathologies. Further, a disturbed LCPUFA metabolism is reported to be associated with a number of metabolic disorders. It is likely that LCPUFA supplementation during early pregnancy may be beneficial in improving the health of the mother, improving birth outcome and thereby reducing the risk of diseases in later life.

Erythrocyte DHA and AA in infancy is not associated with developmental status and cognitive functioning five years later in Nepalese children

BACKGROUND

Long chain polyunsaturated fatty acids (LCPUFA) especially docosahexaenoic acid (DHA) and arachidonic acid (AA) are crucial for normal brain development in utero and in early infancy. Data on fatty acid status and cognitive development in infants and children from low-income countries are scarce.

METHODS

We examined the association between the DHA and AA status in infancy (n = 320) and developmental status and cognitive functioning five years later. At five years of age, we measured development by the Ages and Stages Questionnaire 3rd. ed. (ASQ-3) and cognitive functioning by subtests from the neuropsychological test battery NEPSY II. In addition, infant fatty acid composition in red blood cells (RBC) was analyzed. In multiple linear and logistic regression models, we estimated the associations between DHA and AA status in infancy and scores on the ASQ-3 and the NEPSY II subtests.

RESULTS

There were no notable associations between infant AA and DHA status, and the scores on the ASQ-3 and the NEPSY II subtests five years later. It should be noted that we found better than expected concentrations of erythrocyte DHA and AA among the infants, and the ASQ scores were left-skewed, which limited the ability to identify associations.

CONCLUSION

DHA and AA status in infancy is seemingly not related to neurodevelopment measured 5 years later in this peri-urban population from Nepal.

Evaluation of polyherbal formulation and synthetic choline chloride on choline deficiency model in broilers: implications on zootechnical parameters, serum biochemistry and liver histopathology

Objective

The study was designed to establish choline deficiency model (CDM) in broilers for evaluating efficacy of polyherbal formulation (PHF) in comparison with synthetic choline chloride (SCC).

Methods

A total of 2,550 one-day-old Cobb 430 broiler chicks were randomly assigned to different groups in three experiments. In experiment 1, G1 and G2 served as normal controls and were fed a basal diet with 100% soybean meal (SBM) as a major protein source supplemented with and without SCC, respectively. In G3, G4, G5, and G6 groups, SBM was replaced at 25%, 50%, 75%, and 100% by soy protein isolate (SPI) to induce a graded level of choline deficiency. In experiment 2, PHF (500 and 1,000 g/ton) in comparison with SCC (1,000 g/ton) were evaluated. In experiment 3, dose-response of PHF (200, 400, and 500 g/ton) with SCC (400 g/ton) was determined.

Results

Replacement of SBM by SPI produced a linear decrease in body weight gain (BWG) with a poor feed conversion ratio (FCR). 25% SBM replacement by SPI yielded an optimum negative impact on BWG and FCR; hence, it is considered for further studies. In experiment 2, PHF (500 and 1,000 g/ton) and SCC (1,000 g/ton) showed a similar performance in BWG, FCR and relative liver weight. In experiment 3, PHF produced an optimum efficacy at 400 g/ton and was comparable to SCC in the restoration of serum aspartate aminotransferase activity, abdominal fat, breast muscle lipid content and liver histopathological abnormalities.

Conclusion

Replacement of SBM by SPI caused choline deficiency characterised by worsening of BWG, FCR, elevation in liver enzymes and histopathological changes indicating fatty liver. CDM was found valid for evaluating SCC and PHF. It is concluded that PHF has the potential to mimic biological activities of SCC through the restoration of negative effects caused by CDM.

PERFORMANCE OF BROILERS FED DIFFERENT DIETARY CHOLINE SOURCES AND LEVELS

Abstract Two experiments were carried out to evaluate the bioequivalence of a commercial phosphatidylcholine source (Biocholine™) as an alternative to choline chloride and the choline requirements of broilers of a fast-growth strain. In Experiment I, 672 broilers were fed four Biocholine™ levels (0, 100, 200, or 300 mg/kg) and three choline levels (200, 400, or 600 mg/kg) supplied as choline chloride between 4 and 28 days (d) of age. In Experiment II, 462 broilers received diets supplemented with 0, 200, 400, 600 or 800 mg/kg choline as choline chloride. In both experiments, diets were based on white rice, soybean meal, and corn gluten. In Experiment I, birds fed choline chloride presented higher feed intake than those fed Biocholine™. Both choline supplements linearly improved feed conversion ratio (FCR) between 15 and 28 d, but the curves presented different slopes, showing that one unit (U) of Biocholine™ was equivalent to 2.52 U of choline supplied as choline chloride. In Experiment II, the supplementation of choline had a quadratic effect on weight gain (WG) but did not affect FCR. Choline requirements for WG were determined as 778, 632, and 645 mg/kg for 1-7, 1-35, and 1-42 d of age, respectively.

Reduced Maternal Erythrocyte Long Chain Polyunsaturated Fatty Acids Exist in Early Pregnancy in Preeclampsia

The present prospective study examines proportions of maternal erythrocyte fatty acids across gestation and their association with cord erythrocyte fatty acids in normotensive control (NC) and preeclamptic pregnancies. We hypothesize that maternal fatty acid status in early pregnancy influences fetal fatty acid stores in preeclampsia. 137 NC women and 58 women with preeclampsia were included in this study. Maternal blood was collected at 3 time points during pregnancy (16-20th weeks, 26-30th weeks and at delivery). Cord blood was collected at delivery. Fatty acids were analyzed using gas chromatography. The proportions of maternal erythrocyte α-linolenic acid, docosahexaenoic acid, nervonic acid, and monounsaturated fatty acids (MUFA) (p < 0.05 for all) were lower while total n-6 fatty acids were higher (p < 0.05) at 16-20th weeks of gestation in preeclampsia as compared with NC. Cord 18:3n-3, 22:6n-3, 24:1n-9, MUFA, and total n-3 fatty acids (p < 0.05 for all) were also lower in preeclampsia as compared with NC. A positive association was observed between maternal erythrocyte 22:6n-3 and 24:1n-9 at 16-20th weeks with the same fatty acids in cord erythrocytes (p < 0.05 for both) in preeclampsia. Our study for the first time indicates alteration in maternal erythrocyte fatty acids at 16th weeks of gestation which is further reflected in cord erythrocytes at delivery in preeclampsia.

Transcriptome and Molecular Pathway Analysis of the Hepatopancreas in the Pacific White Shrimp Litopenaeus vannamei under Chronic Low-Salinity Stress

The Pacific white shrimp Litopenaeus vannamei is a euryhaline penaeid species that shows ontogenetic adaptations to salinity, with its larvae inhabiting oceanic environments and postlarvae and juveniles inhabiting estuaries and lagoons. Ontogenetic adaptations to salinity manifest in L. vannamei through strong hyper-osmoregulatory and hypo-osmoregulatory patterns and an ability to tolerate extremely low salinity levels. To understand this adaptive mechanism to salinity stress, RNA-seq was used to compare the transcriptomic response of L. vannamei to changes in salinity from 30 (control) to 3 practical salinity units (psu) for 8 weeks. In total, 26,034 genes were obtained from the hepatopancreas tissue of L. vannamei using the Illumina HiSeq 2000 system, and 855 genes showed significant changes in expression under salinity stress. Eighteen top Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were significantly involved in physiological responses, particularly in lipid metabolism, including fatty-acid biosynthesis, arachidonic acid metabolism and glycosphingolipid and glycosaminoglycan metabolism. Lipids or fatty acids can reduce osmotic stress in L. vannamei by providing additional energy or changing the membrane structure to allow osmoregulation in relevant organs, such as the gills. Steroid hormone biosynthesis and the phosphonate and phosphinate metabolism pathways were also involved in the adaptation of L. vannamei to low salinity, and the differential expression patterns of 20 randomly selected genes were validated by quantitative real-time PCR (qPCR). This study is the first report on the long-term adaptive transcriptomic response of L. vannamei to low salinity, and the results will further our understanding of the mechanisms underlying osmoregulation in euryhaline crustaceans.

Choline Essentiality and Its Requirement in Diets for Juvenile Parrot Fish (Oplegnathus fasciatus)

A 12-wk feeding trial was conducted to evaluate the essentiality of choline supplementation in diets for parrot fish. Five isonitrogenous and isocaloric diets were supplemented with 0 (as control), 500, 1,000, and 2,000 mg choline per kg diet, and a positive control diet without choline contained 0.3% of 2-amino-2-methyl-1-propanol as choline biosynthesis inhibitor (designated as Con, C500, C1000, C2000 and Con⁺, respectively). Triplicate groups of fish (body weight, 8.8±0.01 g) were fed one of the experimental diets at a rate of 4% body weight twice daily. The fish fed Con⁺ diet revealed significantly lower growth performance and feed utilization efficiency than other fish groups. Supplementation of choline to the basal diet did not significantly influence fish growth. The highest liver lipid content was observed in fish fed the Con⁺ diet and inversely correlated with liver choline concentration although the differences were not significant. Also, significantly higher liver linoleic, eicosapentaenoic and docosahexaenoic acid contents were found in fish fed the Con⁺ diet. Innate immune parameters including respiratory burst and myeloperoxidase activities were not significantly affected by dietary choline levels. The findings in this study conclude that choline concentration of approximately 230 mg kg⁻¹ diet meets the requirement of parrot fish.

Prenatal-onset neurodevelopmental disorders secondary to toxins, nutritional deficiencies, and maternal illness

Neurodevelopmental disorders result from an inordinate number of genetic and environmental causes during the embryological and fetal periods of life. In the clinical setting, deciphering precise etiological diagnoses is often difficult. Newer screening technologies allow a gradual shift from traditional nature-versus-nurture debates toward the focused analysis of gene-by-environment interactions (G X E). Further understanding of developmental adaptation and plasticity requires consideration of epigenetic processes such as maternal nutritional status, environmental toxins, maternal illnesses, as well as genetic determinants, alone or in combination. Appreciation of specific G X E mechanisms of neurodevelopmental pathogenesis should lead to better risk-modifying or preventive strategies. We provide a brief overview of clinical and experimental observations that link prenatal-onset toxic exposures, metabolic disturbances, and maternal illnesses to certain neurodevelopmental disorders.

Gene-environment interplay in Drosophila melanogaster: chronic food deprivation in early life affects adult exploratory and fitness traits

Early life adversity has known impacts on adult health and behavior, yet little is known about the gene-environment interactions (GEIs) that underlie these consequences. We used the fruit fly Drosophila melanogaster to show that chronic early nutritional adversity interacts with rover and sitter allelic variants of foraging (for) to affect adult exploratory behavior, a phenotype that is critical for foraging, and reproductive fitness. Chronic nutritional adversity during adulthood did not affect rover or sitter adult exploratory behavior; however, early nutritional adversity in the larval period increased sitter but not rover adult exploratory behavior. Increasing for gene expression in the mushroom bodies, an important center of integration in the fly brain, changed the amount of exploratory behavior exhibited by sitter adults when they did not experience early nutritional adversity but had no effect in sitters that experienced early nutritional adversity. Manipulation of the larval nutritional environment also affected adult reproductive output of sitters but not rovers, indicating GEIs on fitness itself. The natural for variants are an excellent model to examine how GEIs underlie the biological embedding of early experience.

Desnutrição perinatal e o controle hipotalâmico do comportamento alimentar e do metabolismo do músculo esquelético

A deficiência de nutrientes durante os períodos críticos do desenvolvimento tem sido associada com maior risco para desenvolver obesidade e diabetes Mellitus na vida adulta. Um dos mecanismos propostos refere-se à regulação do comportamento alimentar e às alterações do metabolismo energético do músculo esquelético. Recentemente, tem sido proposta a existência de uma comunicação entre o hipotálamo e o músculo esquelético a partir de sinais autonômicos que podem explicar as repercussões da desnutrição perinatal. Assim, esta revisão tem como objetivo discutir as repercussões da desnutrição perinatal sobre o comportamento alimentar e o metabolismo energético muscular e a comunicação existente entre o hipotálamo e o músculo via sinais adrenérgicos. Foram utilizadas as bases de dados MedLine/PubMed, Lilacs e Bireme, com publicações entre 2000 e 2011. Os termos de indexação utilizados foram: feeding behavior, energy metabolism, protein malnutrition, developmental plasticity, skeletal muscle e autonomic nervous system. Concluiu-se que a desnutrição perinatal pode atuar no controle hipotalâmico do comportamento alimentar e no metabolismo energético muscular, e a comunicação hipotálamo-músculo pode favorecer o desenvolvimento de obesidade e comorbidades durante o desenvolvimento.

Early milk availability modulates the activity of choline acetyltransferase in the cerebral cortex of rats

The purpose of the present study was to investigate the effect of milk in the early stage of lactation on the maturation of cholinergic neurons in the cerebral cortex of rats. Pups were removed from their mothers immediately following parturition and placed with foster dams at days 5-7 of lactation. At days 18 and 56 after birth, the activity of choline acetyltransferase (ChAT), an enzyme responsible for acetylcholine synthesis, in different areas of the cerebral cortex was examined by high-performance liquid chromatography electrochemical detection. In the frontal and hindlimb/parietal regions of the cerebral cortex, the lack of early milk significantly decreased ChAT activity at days 18 and 56. There was no effect on gains in the body or brain weight of infants. ChAT activity in the occipital area tended to be lower in the early milk-deprived rats. The intake of early milk potentially contributes not only to nutrients for the growth of newborn infants, but also to the functional maturation of the cholinergic neurotransmission system in a region-specific manner.

Nutrition and neurodevelopment: mechanisms of developmental dysfunction and disease in later life

Nutrition plays a central role in linking the fields of developmental neurobiology and cognitive neuroscience. It has a profound impact on the development of brain structure and function and malnutrition can result in developmental dysfunction and disease in later life. A number of diseases, including schizophrenia, may be related to neurodevelopmental insults such as malnutrition, hypoxia, viruses or in utero drug exposure. Some of the most significant findings on nutrition and neurodevelopment during the last three decades, and especially during the last few years, are discussed in this review. Attention is focused on the underlying cellular and molecular mechanisms by which diet exerts its effects. Randomized intervention studies have revealed important effects of early nutrition on later cognitive development, and recent epidemiological findings show that both genetics and environment are risk factors for schizophrenia. Particularly important is the effect of early nutrition on development of the hippocampus, a brain structure important in establishing learning and memory, and hence for cognitive performance. A major aim of future research should be to elucidate the molecular mechanisms underlying nutritionally-induced impairment of neurodevelopment and specifically to determine the mechanisms by which early nutritional experience affects later cognitive performance. Key research objectives should include: (1) increased understanding of mechanisms underlying the normal processes of ageing and neurodegenerative disorders; (2) assessment of the role of susceptibility genes in modulating the effects of early nutrition on neurodevelopment; and (3) development of nutritional and pharmaceutical strategies for preventing and/or ameliorating the adverse effects of early malnutrition on long-term programming.

Micronutrient supplementation affects maternal-infant feeding interactions and maternal distress in Bangladesh

BACKGROUND

Good maternal-infant interaction is essential for optimal infant growth, health, and development. Although micronutrient malnutrition has been associated with poorer interaction, the effects of maternal micronutrient supplementation on interaction are unknown.

OBJECTIVES

We examined differences in maternal-infant feeding interaction between 3 maternal pre- and postpartum micronutrient supplementation groups that differed in iron dose and inclusion of multiple micronutrients and determined whether any differences observed were mediated by maternal distress.

DESIGN

A cohort of 180 pregnant women was selected from 3300 women in the randomized controlled trial Maternal Infant Nutritional Interventions Matlab, which was conducted in Matlab, Bangladesh. At 8 wk of gestation, women were randomly assigned to 1 of 3 groups to receive a daily supplement of micronutrients (14 wk gestation to 12 wk postpartum): 60 or 30 mg Fe each with 400 microg folic acid or multiple micronutrients (MuMS; 30 mg Fe, 400 microg folic acid, and other micronutrients). A maternal-infant feeding interaction was observed in the home when infants were 3.4-4.0 mo of age, and maternal distress was assessed.

RESULTS

Compared with 30 mg Fe, 60 mg Fe decreased the quality of maternal-infant feeding interaction by approximately 10%. Compared with 30 mg Fe, MuMS did not improve interaction but reduced maternal early postpartum distress. Distress did not mediate the effects of micronutrient supplementation on interaction.

CONCLUSION

For pregnant and postpartum women, micronutrient supplementation should be based on both nutritional variables (eg, iron status) and functional outcomes (eg, maternal-infant interaction and maternal distress).

Methylmercury and nutrition: adult effects of fetal exposure in experimental models

Human exposure to the life-span developmental neurotoxicant, methylmercury (MeHg), is primarily via the consumption of fish or marine mammals. Fish are also excellent sources of important nutrients, including selenium and n-3 polyunsaturated fatty acids (PUFAs), such as docosahexaenoic acid (DHA). Laboratory models of developmental MeHg exposure can be employed to assess the roles of nutrients and MeHg and to identify potential mechanisms of action if the appropriate exposure measures are used. When maternal exposure is protracted, relationships between daily intake and brain mercury are consistent and orderly across species, even when large differences in blood:brain ratios exist. It is well established that low-level developmental MeHg produces sensory deficits. Recent studies also show that perseveration in reversal-learning tasks occurs after gestational exposures that produce low micromolar concentrations in the brain. A no-effect level has not been identified for this effect. These exposures do not affect the acquisition or performance of discrimination learning, set shifting (extradimensional shift), or memory. Reversal-learning deficits may be related to enhanced impact of reinforcers as measured using progressive ratio reinforcement schedules, an effect that could result in perseveration. Also reported is enhanced sensitivity to dopamine reuptake inhibitors and diminished sensitivity to pentobarbital, a GABA(A) agonist. Diets rich in PUFAs or selenium do not protect against MeHg's effects on reversal learning but, by themselves, may diminish variability in performance, enhance attention or psychomotor function and may confer some protection against age-related deficits in these areas. It is hypothesized that altered reward processing, dopamine and GABAergic neurotransmitter systems, and cortical regions associated with choice and perseveration are especially sensitive to developmental MeHg at low exposure levels. Human testing for MeHg's neurotoxicity should emphasize these behavioral domains.

Nutritional factors in a mouse model of Rett syndrome

Environmental factors such as nutrition and housing can influence behavioral and anatomical characteristics of several neurological disorders, including Rett syndrome (RTT). RTT is associated with mutations in the X-linked gene encoding MeCP2, a transcriptional repressor that binds methylated DNA. While direct genetic intervention in humans is impossible at this time, motor and cognitive deficits in RTT may be ameliorated through manipulations of epigenetic/environmental factors. For example, studies in rodents suggest that choline nutrient supplementation during critical periods of brain development enhances cholinergic neurotransmission, alters neuronal size and distribution, and facilitates performance of memory and motoric tasks. Recent work in a mouse model of RTT shows that enhancing maternal nutrition through choline supplementation improves both anatomical and behavioral symptoms in the mutant offspring. We describe here cellular and molecular mechanisms that may underlie this specific enhancement and may provide more general insights into mechanisms underlying gene-environment interactions in neurological disorders.

An overview of evidence for a causal relation between iron deficiency during development and deficits in cognitive or behavioral function

This review, intended for a broad scientific readership, summarizes evidence relevant to whether a causal relation exists between dietary iron deficiency with (ID+A) or without (ID-A) anemia during development and deficits in subsequent cognitive or behavioral performance. An overview of expert opinion and major evidence in humans and animals is provided. Cognitive and behavioral effects observed in humans with ID-A and in animals with ID+/-A are provided in tables. The degree to which 5 conditions of causality are satisfied and whether deleterious effects of ID-A might be expected to occur are discussed. On the basis of the existing literature, our major conclusions are as follows. Although most of the 5 conditions of causality (association, plausible biological mechanisms, dose response, ability to manipulate the effect, and specificity of cause and effect) are partially satisfied in humans, animals, or both, a causal connection has not been clearly established. In animals, deficits in motor activity are consistently associated with severe ID+A, but adverse effects on performance in tests that target cognitive function have not been clearly shown. Resistance to iron treatment was observed in most trials of children <2 y of age with ID+A, but not in older children. Similar observations were made in rodents when ID+A occurred before rather than after weaning. In children >2 y of age and in adolescents with ID-A, evidence suggests cognitive or behavioral deficits; however, the surprisingly small number of studies conducted in either humans or animals prevents a thorough assessment.

Mental and psychomotor development in Indonesian infants of mothers supplemented with vitamin A in addition to iron during pregnancy

Maternal nutrition is important for fetal development, but its impact on the functional outcome of infants is still unclear. The present study investigated the effects of vitamin A and Fe supplementation during gestation on infant mental and psychomotor development. Mothers of infants from five villages in Indonesia were randomly assigned to supervised, double-blind supplementation once per week from approximately 18 weeks of pregnancy until delivery. Supplementation comprised 120 mg Fe + 500 μg folic acid with (n94) or without (n94) 4800 μg retinol in the form of retinyl acetate. Mothers of infants who participated in the national Fe+folic acid supplementation programme, but whose intake of supplements was not supervised, were recruited from four other villages (n88). The mental and psychomotor development of infants was assessed, either at 6 or 12 months of age, using the Bayley Scales of Infant Development (BSID). We found no impact of vitamin A supplementation on mental or psychomotor development of infants. In addition, infants whose mothers had received weekly Fe supplementation had similar mental and psychomotor indices as those whose mothers had participated in the governmental Fe supplementation programme. The study population was moderately Fe and vitamin A deficient. The size of the treatment groups was large enough to detect a mean difference of 10 points on the BSID, which is less than 1 sd (15 points) of the average performance of an infant on the BSID. In conclusion, the present study did not find an impact of weekly supplementation of 4800 RE vitamin A in addition to Fe during gestation on functional development of Indonesian infants. However, smaller improvements in development may be seen if studied in a larger and/or more deficient population.

L-threo 3,4-dihydroxyphenylserine treatment during mouse perinatal and rat postnatal development does not alter the impact of dietary copper deficiency

Dietary copper (Cu) deficiency was induced perinatally in Swiss Albino mice and postnatally in male Holtzman rats to investigate the effect of L-threo 3,4-dihydroxyphenylserine (DOPS) on pup survival and catecholamine levels in a 2 x 2 factorial design. Mouse dams were placed on one of four treatments 14 days after mating and rats at postnatal day 19 (P19). Treatments were Cu-adequate (Cu + ) and Cu-deficient (Cu - ) diets with or without DOPS (1 mg/ml) in the drinking water. Mouse pups were killed at P14 and rats at P49. Mortality in Cu - pups was 46% and not significantly improved by DOPS, 39%. A repeat study with mice adding ascorbic acid in the water with DOPS showed no improvement. Compared to Cu + animals, Cu - animals were smaller, anemic and had a 92% reduction in liver Cu. DOPS treatment made no improvement to and in some cases exacerbated the Cu deficiency. Catecholamine levels measured in heart and brain by LCEC showed decreased NE levels and increased DA levels in Cu - animals compared to controls. DOPS treatment did not alter this pattern. Although DOPS was present in treated animal's tissues, survival in mice and catecholamine levels in mice and rats were not altered by the 1 mg/ml dose of DOPS.

Neuromotor deficits and mercury concentrations in rats exposed to methyl mercury and fish oil

It has been suggested that docosahexaenoic acid (DHA) or other n-3 polyunsaturated fatty acids (PUFAs) may prevent or ameliorate methyl mercury's neurotoxicity. To examine interactions between PUFAs and methyl mercury exposure, sixty-six female Long-Evans rats were exposed to methyl mercury continuously via drinking water from fifteen weeks of age. Water included methyl mercury concentrations of 0, 0.5, and 5.0 ppm, creating estimated intakes of about 0, 40, and 400 microg/kg/day across exposure groups. An additional fifty-eight female offspring were exposed to methyl mercury only during gestation. Rats consumed one of two diets, each based on AIN-93 formulation, providing a 2 (generation) X 2 (diet) X 3 (methyl mercury exposure) factorial experimental design. A "coconut oil" diet (1/3 of fats were provided by coconut oil) was marginally adequate in n-3 PUFAs and contained no DHA. A "fish oil" diet was rich in n-3 fatty acids, including DHA. The diets were approximately equal in n-6 fatty acids. Forelimb grip strength declined with age for all groups, but the decline was greatest for those exposed chronically to 400 microg/kg/day of methyl mercury. This high-dose group also displayed hind limb crossing, gait disorders, and diminished running wheel activity. Dietary n-3 fatty acids did not influence these effects. Chronic exposure to 400 microg/kg/day of methyl mercury resulted in blood and brain concentrations of about 70 and 10 ppm, respectively, approximately 50-fold higher than concentrations seen in rats exposed to 40 microg/kg/day. Rats that became ill and died before the experiment ended had higher concentrations of mercury than their cohorts who survived to the end. Organic mercury was highly correlated with total mercury in these rats but inorganic mercury remained approximately constant. Some deaths were due to urolithiasis (kidney or bladder stones) associated with a dietary contaminant and that was eventually fatal to 22% of the females in the colony. Neurobehavioral effects are reported on rats that did not become ill.

Is docosahexaenoic acid, an n-3 long-chain polyunsaturated fatty acid, required for development of normal brain function? An overview of evidence from cognitive and behavioral tests in humans and animals

This review is part of a series intended for nonspecialists that will summarize evidence relevant to the question of whether causal relations exist between micronutrient deficiencies and brain function. Here, we focus on experiments that used cognitive or behavioral tests as outcome measures in experimental designs that were known to or were likely to result in altered brain concentrations of the n-3 fatty acid docosahexaenoic acid (DHA) during the perinatal period of "brain growth spurt." Experimental designs reviewed include observational breastfeeding studies and randomized controlled trials in humans and studies in rodents and nonhuman primates. This review is based on a large number of expert reviews and commentaries and on some 50 recent studies in humans and animals that have not yet been included in published reviews. Expert opinion regarding the strengths and weaknesses of the major experimental systems and uncertainties associated with interpreting results is summarized. On the basis of our reading of this literature, we conclude that evidence from several types of studies, particularly studies in animals, suggests that, within the context of specific experimental designs, changes in brain concentrations of DHA are positively associated with changes in cognitive or behavioral performance. Additional experimental information required to conclude that a causal association exists is discussed, as are uncertainties associated with applying results from specific experimental designs to the question of whether infant formula should be supplemented with DHA.

Rat brain iron concentration is lower following perinatal copper deficiency

Experiments performed with Holtzman rats demonstrated that brain iron (Fe) was lower by postnatal day 13 (P13) in pups born and nursed by dams that began copper-deficient (-Cu) treatment at embryonic day 7. Transcardial perfusion of P24-P26 males and females to remove blood Fe contamination revealed that brain Fe was still 20% lower in -Cu than +Cu rats. Estimated blood content of brain for -Cu rats was greater than for +Cu rats; for all groups, values ranged between 0.43 and 1.03%. Using group-specific data and regression analyses, r = 0.99, relating blood Fe to hemoglobin, brain Fe in non-perfused rats in a replicate study was lower by 33% at P13 and 39% at P24 in -Cu rats. Brain extracts from these rats and from P50 rats from a post-weaning model were compared by immunoblotting for transferrin receptor (TfR1). P24 brain -Cu/+Cu TfR1 was 3.08, suggesting that brains of -Cu rats were indeed Fe deficient. This ratio in P13 rats was 1.44, p < 0.05. No change in P50 -Cu rat brain TfR1 or Fe content was detected despite a 50% reduction in plasma Fe. The results suggest that brain Fe accumulation depends on adequate Cu nutriture during perinatal development.

Abnormal motor function persists following recovery from perinatal copper deficiency in rats

What are the biochemical and behavioral consequences of perinatal copper deficiency? Pregnant Holtzman rats were fed a modified AIN-76A diet low in copper (0.34 mg Cu/kg and 42 mg Fe/kg) starting on gestation d 7. Seven rats received copper in their drinking water (20 mg Cu/L) (+Cu) and 7 drank deionized water (-Cu). Treatments did not affect litter size or pregnancy outcome. Compared with +Cu dams and a sample of +Cu male weanling [postnatal day (P)21] offspring, -Cu rats exhibited signs consistent with copper deficiency. P21 males were switched to a nonpurified copper-adequate diet and sampled biochemically after 3 mo and behaviorally after 3 and 6 mo of repletion (CuR). Compared with controls, CuR rats had lower brain copper and iron levels 3 and 6 mo after repletion; other biochemical differences were not detected. Behavioral assessments after 5 mo of repletion indicated a persistent impairment in motor function of CuR compared with control rats as evaluated by the accelerating rotorod procedure. These results suggest that permanent impairment to motor function can persist after long-term recovery from perinatal copper deficiency.

Nutrition and brain function: a multidisciplinary virtual symposium

A few months ago, the Brazilian Society for Neuroscience and Behavior (SBNeC) promoted a "virtual symposium" (by Internet, under the coordination of R.C.A. Guedes) on "Nutrition and Brain Function". The discussions generated during that symposium originated the present text, which analyzes current topics on the theme, based on the multidisciplinary experience of the authors. The way the brain could be non-homogeneously affected by nutritional alterations, as well as questions like early malnutrition and the development of late obesity and hormone abnormalities were discussed. Also, topics like the role of essential fatty acids (EFAs) on brain development, increased seizure susceptibility and changes in different neurotransmitters and in cognitive performance in malnourished animals, as well as differences between overall changes in nutrient intake and excess or deficiency of specific nutrients (e.g. iodine deficiency) were analyzed. It was pointed out that different types of neurons, possibly in distinct brain structures, might be differently affected by nutritional manipulation, including not only lack-but also excess of nutrient intake. Such differences could help in explaining discrepancies between data on humans and in animals and so, could aid in determining the basic mechanisms underlying lesions or changes in brain function and behavior.

Red blood cell and plasma phospholipid arachidonic and docosahexaenoic acid levels at birth and cognitive development at 4 years of age

OBJECTIVE

The long-chain polyunsaturated fatty acids (LCPUFAs) docosahexaenoic acid (DHA) and arachidonic acid (AA) have biophysical properties that may mediate behavioral outcome, especially cognitive development. This study examined the relationship between the LCPUFA-status at birth and cognitive development at 4 years of age.

METHODS

Cognitive development of 128 full-term neonates, whose umbilical venous plasma and/or red blood cell phospholipid DHA and AA levels were known, was assessed at 4 years of age. Pearson correlation coefficients were calculated between cognitive development and DHA, AA, maternal intelligence, birth weight, duration of breast-feeding and paternal educational attainment. Multiple linear regressions were employed with cognitive development as the dependent variable and whereby the above-mentioned covariables were entered in step one while each of the four LCPUFAs was entered in step two.

RESULTS

In bivariate analysis, maternal intelligence, birth weight, maternal smoking habits during pregnancy, paternal education and duration of breast-feeding showed significant correlations with cognitive development (p<0.01). The association of cognitive development with DHA and AA measured zero in bivariate analysis (plasma levels: r=0.03 and r=-0.03, respectively; erythrocyte levels: r=0.01 and r=0.05) and in multiple regression analysis (plasma DHA r=0.01, p=0.88; plasma AA r=0.02, p=0.80; erythrocyte DHA r=-0.01, p=0.95) except for erythrocyte AA (r=0.15, p=0.09).

CONCLUSION

No evidence was found for an association of the DHA or AA-status at birth with cognitive development at 4 years of age.

Dietary essential fatty acids and brain function: a developmental perspective on mechanisms

Brain development is a complex interactive process in which early disruptive events can have long-lasting effects on later functional adaptation. It is a process that is dependent on the timely orchestration of external and internal inputs through sophisticated intra- and intercellular signalling pathways. Long-chain polyunsaturated fatty acids (LCPUFA), specifically arachidonic acid and docosahexaenoic acid (DHA), accrue rapidly in the grey matter of the brain during development, and brain fatty acid (FA) composition reflects dietary availability. Membrane lipid components can influence signal transduction cascades in various ways, which in the case of LCPUFA include the important regulatory functions mediated by the eicosanoids, and extend to long-term regulation through effects on gene transcription. Our work indicates that FA imbalance as well as specific FA deficiencies can affect development adversely, including the ability to respond to environmental stimulation. For example, although the impaired water-maze performance of mice fed a saturated-fat diet improved in response to early environmental enrichment, the brains of these animals showed less complex patterns of dendritic branching. Dietary n-3 FA deficiency influences specific neurotransmitter systems, particularly the dopamine systems of the frontal cortex. We showed that dietary deficiency of n-3 FA impaired the performance of rats on delayed matching-to-place in the water maze, a task of the type associated with prefrontal dopamine function. We did not, however, find an association over a wider range of brain DHA levels and performance on this task. Some, but not all, studies of human infants suggest that dietary DHA may play a role in cognitive development as well as in some neurodevelopmental disorders; this possibility has important implications for population health.

The role of nutritional factors in behavioural development in laboratory mice

This paper addresses the importance of considering nutritional factors as a source of variability in studies of behavioural development in mice. Work in our laboratory, using a standardised developmental scale that allows quantitative comparisons among different studies, indicates that nutritional factors do have the propensity to influence behavioural development to a degree similar to that seen with some genotypic manipulations. These nutritional factors encompass both undernutrition, which entails an overall reduction in nutrient and caloric intake, and malnutrition, which refers to a dietary imbalance, i.e. a deficiency (or excess) of specific macro- or micronutrients. As an example of malnutrition, we describe investigations in mice that address the role of the essential fatty acids in brain and behavioural development. These show that manipulations of dietary lipid composition that are in the same range that one would find among commercial laboratory diets influence not only behavioural development, but also performance on other behavioural tasks. This suggests that detailed dietary information may be useful in the attempt to characterise the sources of variation in the behavioural phenotypes of mice.

Zinc and cognitive development

Cognition is a field of thought processes by which an individual processes information through skills of perception, thinking, memory, learning and attention. Zinc deficiency may affect cognitive development by alterations in attention, activity, neuropsychological behavior and motor development. The exact mechanisms are not clear but it appears that zinc is essential for neurogenesis, neuronal migration, synaptogenesis and its deficiency could interfere with neurotransmission and subsequent neuropsychological behavior. Studies in animals show that zinc deficiency during the time of rapid brain growth, or during the juvenile and adolescent period affects cognitive development by decreasing activity, increasing emotional behavior, impairing memory and the capacity to learn. Evidence from human studies is limited. Low maternal intakes of zinc during pregnancy and lactation were found to be associated with less focused attention in neonates and decreased motor functions at 6 months of age. Zinc supplementation resulted in better motor development and more playfulness in low birth weight infants and increased vigorous and functional activity in infants and toddlers. In older school going children the data is controversial but there is some evidence of improved neuropsychological functions with zinc supplementation. Additional research is required to determine the exact biological mechanisms, the critical periods, the threshold of severity and the long-term effects of zinc deprivation on cognitive development.

Chronic pulmonary insufficiency in children and its effects on growth and development

Conditions leading to chronic pulmonary insufficiency can affect infants and children. These can lead to growth failure and delayed development. Among the most common and severe of these are bronchopulmonary dysplasia (BPD) and cystic fibrosis. In addition to the respiratory consequences of these diseases, there is ample evidence that they lead to decreased growth as a result of decreased energy intake and increased energy expenditure. Furthermore, there is evidence that infants with BPD may also have delayed development, independent of the effects of their prematurity. Enhancing the long-term outlook for these conditions may therefore require consideration of both improved pulmonary management and aggressive nutritional management to limit growth failure and potentially enhance developmental outcome. Specific micronutrient supplementation, such as antioxidant therapy, may also enhance pulmonary and nutritional status.

Perinatal ontogeny of brain growth in the domestic pig

The perinatal development of the brain is highlighted by a growth spurt whose timing varies among species. The growth of the porcine cerebrum was investigated from the third trimester of gestation (70 days postconception) through the first 3.5 weeks of postnatal life (140 days postconception). The shape of the growth curves for cerebrum weight, total protein mass, total cell number (estimated by DNA content), and myelination (estimated by cholesterol accretion) were described. The growth velocity of cerebrum weight had two peaks, one at 90 days and the other at 130 days postconception, whereas that of total protein was greatest from 90 to 130 days postconception, and that of total DNA was greatest between 90 and 110 days and again at 130 days postconception. The growth velocity for total cholesterol continued to increase during the entire period, suggesting that myelination continued after the growth spurts for cells (protein and DNA). The growth velocity patterns observed in these contemporary pigs suggest that this species may be an appropriate model for human brain development, not only in the perinatal pattern of increase in mass of the cerebrum, as established previously, but also with regard to the patterns of cellular development and myelination.