learning difficulties

Air pollution during pregnancy linked to cognitive impairment in children

  • A largish study involving school-age children not at any particular risk has found that higher levels of air pollution experienced by the mother during pregnancy are linked to less gray matter in some brain regions.

Research using data from a population-based birth cohort from Rotterdam, in The Netherlands, has found that children exposed to higher levels of air pollution when they were in womb had significantly thinner cortex in several brain regions. Some of this appeared to be related to impaired inhibitory control.

The study involved 783 children aged 6 to 10, who were given brain imaging and cognitive tests. Levels of air pollution in the mother’s environment during pregnancy were estimated using a standardized procedure. Mean fine particle levels were 20.2 μg/m3, and nitrogen dioxide levels were 39.3μg/m3. Note that the EU limit for mean fine particles is actually above that (25μg/m3), while the NO2 level is at the EU limit (40μg/m3), with 45% of the Dutch population experiencing higher levels. The World Health Organization sets a much lower level for fine particles: 10 μg/m3.

Children whose mothers were smokers were excluded from the study, as were children from areas where pollution measures weren’t available. Children included tended to be from a higher socio-economic position compared to those not included. Moreover, children with ADHD, or developmental or behavioral problems, were also excluded.

Global brain volume was not affected by fetal exposure. However, several brain regions showed significantly thinner cortex — in particular, the precuneus and rostral middle frontal regions, which partially accounted for the observed association between fetal exposure to fine particles and impaired inhibitory control (the ability to control your own behavior, especially impulsive behavior). This sort of cognitive impairment at early ages could have significant long-term consequences in academic achievement, later career success, and even in risk of mental disorders.

The findings are consistent with other studies linking acceptable air pollution levels with problems including cognitive impairment and child development.

https://www.eurekalert.org/pub_releases/2018-03/e-apl030818.php

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The wrong genes mean even moderate drinking in pregnancy can affect a child's IQ

December, 2012

A large study suggests that even a few drinks a week can negatively affect the developing fetus, but only if the woman has specific gene variants.

It’s always difficult in human studies to disentangle the effects of lifestyle factors. Alcohol is a case in point, and in particular the vexed question of whether any alcohol is safe during pregnancy. A new study, however, has avoided the complication of co-occurring lifestyle and environment factors by looking directly at genetic variants.

This study, believed to be the first substantial one of its kind, used genetic variation to investigate the effects of moderate (<6 units of alcohol per week) drinking during pregnancy among a large group of women and their children. Since the individual variations that people have in their DNA are not connected to lifestyle and social factors, the approach removes that potential complication.

The study, involving 4,167 children, found that four genetic variants in alcohol-metabolizing genes were strongly related to lower IQ at age eight. But this effect was only seen among the children of women who were moderate drinkers (heavy drinkers were not included in the study), pointing to the effect requiring exposure to alcohol in the womb.

Ten SNPs from four genes previously implicated in alcohol metabolism, intake, or dependency, were analyzed. Four SNPs (particular variants) were related to children’s scores on the cognitive test (WISC), of which three are rare and one quite common. There was an additive effect, with carriers of multiple ‘bad’ alleles being more affected.

There was some evidence that only drinking one or two drinks a week was not harmful to the fetus, but because the numbers of women were relatively small, and individual variability was high, this can’t be assessed with any great certainty.

The critical factor appears to be metabolism of alcohol, with mothers who are ‘fast' metabolizers being safer for their fetus than mothers who metabolize alcohol more slowly.

Mothers' alcohol intake was based on questionnaires completed when they were 18 weeks and 32 weeks pregnant. ‘Moderate’ was defined as between one and six drinks a week. All participants were of white-European origin.

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Learning difficulties

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Older news items (pre-2010) brought over from the old website

New screening tool helps identify children at risk

An exam, called the NICU (neonatal intensive care unit) Network Neurobehavioral Scale (NNNS), has been created to identify newborns who may have problems with school readiness and behavior at age four. This opens up the possibility of early intervention to prevent these problems. The screening exam has been tested on 1248 babies, mostly black and on public assistance. Five discrete behavioral profiles were reliably identified; the most extreme negative profile was found in 5.8% of the infants. Infants with poor performance were more likely to have behavior problems at age three, school readiness problems at age four, and low IQ at 4 ½ — 40% had clinically significant problems externalizing (impulsivity and acting out), internalizing (anxiety, depression, withdrawn personalities), and with school readiness (delays in motor, concepts and language skills), and 35% had low IQ.

[596] Liu J, Bann C, Lester B, Tronick E, Das A, Lagasse L, Bauer C, Shankaran S, Bada H. Neonatal neurobehavior predicts medical and behavioral outcome. Pediatrics [Internet]. 2010 ;125(1):e90-98 - e90-98. Available from: http://www.ncbi.nlm.nih.gov/pubmed/19969621

http://www.eurekalert.org/pub_releases/2009-12/bu-nst120709.php

Cognitive dysfunction reversed in mouse model of Down syndrome

Down syndrome is characterized by specific learning impairments (for example, difficulties in using spatial and contextual information to form new memories, but less difficulty at remembering information linked to sensory cues) that point to the hippocampus as a problem area. Investigation has revealed that the problem lies in degeneration of the locus coeruleus, which sends norepinephrine to neurons in the hippocampus. Now a study using genetically engineered mice has found that norepinephrine precursor drugs improved performance in the mice within a few hours. However, the effect did wear off quite quickly too. Other research has looked at acetylcholine, which also acts at the hippocampus. The present findings suggest the best medication regimen will be one that improves both norepinephrine and acetylcholine signals. Locus coeruleus degeneration is also seen in dementia; Alzheimer’s develops among those with Down syndrome at a significantly higher rate than in the general population.

Salehi, A. et al. 2009. Restoration of Norepinephrine-Modulated Contextual Memory in a Mouse Model of Down Syndrome. Science Translational Medicine, 1 (7), 7-17.

http://www.eurekalert.org/pub_releases/2009-11/sumc-nds111309.php
http://www.eurekalert.org/pub_releases/2009-11/uoc--cdr111609.php http://www.the-scientist.com/blog/display/56154/

Testing one time is not enough

A study demonstrating the perils of one-time testing gave 16 common cognitive and neuropsychological tests to groups of people ages 18-39, 50-59 and 60-97 years. The variation between scores on the same test given three times during a two-week period was as big as the variation between the scores of people in different age groups. “It's as if on the same test, someone acted like a 20-year-old on a Monday, a 45-year-old on Friday, and a 32-year-old the following Wednesday”. The study makes clear the dangers of diagnosing learning disability, progressive brain disease or impairment from head injury on the basis of testing on a single occasion. The researcher suggests we should view cognitive abilities as a distribution of many potential levels of performance instead of as one stable short-term level; that people have a range of typical performances, a one-person bell curve. It may also be that within-person variability could be a useful diagnostic marker in itself — for example, extreme fluctuations might be an early warning of mental decline.

[921] Salthouse TA. Implications of within-person variability in cognitive and neuropsychological functioning for the interpretation of change. Neuropsychology [Internet]. 2007 ;21(4):401 - 411. Available from: http://www.ncbi.nlm.nih.gov/pubmed/17605573

http://www.physorg.com/news102689828.html
http://www.eurekalert.org/pub_releases/2007-07/apa-csv062507.php

Common cholesterol-lowering drug reverses learning disabilities in mice

Following their discovery that neurofibromatosis 1 (NF1) — the leading genetic cause of learning disabilities — is linked to dysfunction in a protein called Ras, researchers have successfully used a commonly prescribed cholesterol-lowering statin drug (lovastatin) to reverse the learning deficits in mice. Clinical trials with humans are being planned.

[1348] Li W, Cui Y, Kushner S, Brown R, Jentsch J, Frankland P, Cannon T, Silva A. The HMG-CoA Reductase Inhibitor Lovastatin Reverses the Learning and Attention Deficits in a Mouse Model of Neurofibromatosis Type 1. Current Biology [Internet]. 2005 ;15(21):1961 - 1967. Available from: http://www.cell.com/current-biology/abstract/S0960-9822(05)01113-9

http://www.eurekalert.org/pub_releases/2005-11/uoc--rf110405.php
http://www.newscientist.com/channel/health/dn8276

More light on a common developmental disorder

Chromosome 22q11.2 deletion syndrome is the most common genetic deletion syndrome, and causes symptoms such as heart defects, cleft palate, abnormal immune responses and cognitive impairments. Two related studies have recently cast more light on these cognitive impairments. Previously it was known that numerical abilities were impaired more than verbal skills. The new study found children with the chromosome deletion performed more poorly on experiments designed to test visual attention orienting, enumerating, and judging numerical magnitudes. All three tasks relate to how the children mentally represent objects and the spatial relationships among them, supporting previous arguments that such visual-spatial skills are a fundamental foundation to the later learning of counting and mathematics. The second study found that such children had changes in the shape, size and position of the corpus callosum, the main bridge between the two hemispheres.

[1139] Simon TJ, Bearden CE, Mc-Ginn DMD, Zackai E. Visuospatial and Numerical Cognitive Deficits in Children with Chromosome 22Q11.2 Deletion Syndrome. Cortex [Internet]. 2005 ;41(2):145 - 155. Available from: http://www.sciencedirect.com/science/article/B8JH1-4S0JBRK-7/2/ad6567fc8ae7be0ddb6387920387fc1a

[812] Simon TJ, Ding L, Bish JP, McDonald-McGinn DM, Zackai EH, Gee J. Volumetric, connective, and morphologic changes in the brains of children with chromosome 22q11.2 deletion syndrome: an integrative study. NeuroImage [Internet]. 2005 ;25(1):169 - 180. Available from: http://www.ncbi.nlm.nih.gov/pubmed/15734353

http://www.eurekalert.org/pub_releases/2005-03/chop-lbt030205.php

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Prenatal dangers

Older news items (pre-2010) brought over from the old website

Too much licorice in pregnancy may affect child's IQ and behavior

A Finnish study involving 321 eight year old children has found that those whose mothers ate more than 500mg of glycyrrhizin per week (found in the equivalent of 100g of pure licorice) had significant decrements in verbal and visuospatial abilities and in narrative memory, compared to those whose mothers consumed less licorice. They were also more likely to have poor attention spans and show disruptive behaviour such as ADHD. The effects on cognitive performance appeared dose related (that is, higher consumption correlated with greater impairment). Glycyrrhizin may impair the placenta, allowing stress hormones to cross from the mother to the baby. These hormones (glucocorticoids) are thought to affect fetal brain development and have been linked to behavioural disorders in children. Consumption of licorice among young women is common in Finland.

Raikkonen, K., Pesonen, A., Heinonen, K., Lahti, J., Komsi, N., Eriksson, J. G., et al. (2009). Maternal Licorice Consumption and Detrimental Cognitive and Psychiatric Outcomes in Children. Am. J. Epidemiol., 170(9), 1137-1146. doi: 10.1093/aje/kwp272.

http://www.eurekalert.org/pub_releases/2009-10/uoe-eli100609.php

Vitamin C deficiency impairs early brain development

A guinea pig study has found that newborn guinea pigs subjected to moderate vitamin C deficiency had 30% fewer hippocampal neurons and markedly worse spatial memory than guinea pigs given a normal diet. For several reasons the neonatal brain is thought to be particularly vulnerable to even a slight lowering of the vitamin C level. Vitamin C deficiency is very common in some parts of the world, and even in wealthy nations occurs in an estimated 5-10% of the adult population.

Tveden-Nyborg, P. et al. 2009. Vitamin C deficiency in early postnatal life impairs spatial memory and reduces the number of hippocampal neurons in guinea pigs. American Journal of Clinical Nutrition, 90 (3), 540-546.

http://www.eurekalert.org/pub_releases/2009-09/uoc-vcd090209.php

Children of older fathers perform less well in intelligence tests during infancy

Reanalysis of a dataset of over 33,000 children born between 1959 and 1965 and tested at 8 months, 4 years, and 7 years, has revealed that the older the father, the more likely the child was to have lower scores on the various tests used to measure the ability to think and reason, including concentration, learning, memory, speaking and reading skills. In contrast, the older the mother, the higher the scores of the child in the cognitive tests.

Saha, S. et al. 2009. Advanced paternal age is associated with impaired neurocognitive outcomes during infancy and childhood. PLoS Medicine 6(3), e1000040. doi:10.1371/journal.pmed.1000040 
Full text available at http://medicine.plosjournals.org/perlserv/?request=get-document&doi=10.1371/journal.pmed.1000040

http://www.eurekalert.org/pub_releases/2009-03/plos-coo030309.php

Early maternal experience can affect memory in her offspring

A study of pre-adolescent mice with a genetically-created defect in memory has found that a mere two weeks exposure to a stimulating environment resulted in a reversal of the memory defect. But most surprisingly, it was also found that this effect was passed on to the next generation, even though they had the same genetic defect and even though they had no such experience themselves, and even when they were reared by other mice (not their mothers). It’s worth emphasising that the enrichment occurs for the mother long before she’s fertile, yet still benefits her offspring. The finding adds to many recent studies showing that genes are more malleable than we thought.

Arai, J., Li, S., Hartley, D.M. & Feig, L.A. 2009. Transgenerational Rescue of a Genetic Defect in Long-Term Potentiation and Memory Formation by Juvenile Enrichment. Journal of Neuroscience, 29(5), 1496-1502.

http://www.physorg.com/news152905156.html
http://www.eurekalert.org/pub_releases/2009-02/rumc-wym020209.php
http://www.eurekalert.org/pub_releases/2009-02/tuhs-dyk012909.php

Breaking fish advice during pregnancy may benefit babies

Fears of the effects of mercury have led to government warnings to pregnant women to limit their consumption of seafood. However, a study involving nearly 12,000 women has found that children whose mothers ate the least amount of seafood during pregnancy showed the worst performance on tests of social development and verbal IQ, and beneficial effects were evident among children of women who ate more than the recommended guidelines.

Hibbeln, J.R. et al. 2007. Maternal seafood consumption in pregnancy and neurodevelopmental outcomes in childhood (ALSPAC study): an observational cohort study. The Lancet,369 (9561), 578-585.

http://www.newscientist.com/article/dn11193-breaking-fish-advice-during-pregnancy-might-benefit-babies.html

Ingredient commonly found in shampoos may inhibit brain development

An ingredient found in many shampoos and other personal care products (Diethanolamine (DEA)) appears to interfere with normal brain development in baby mice when applied to the skin of their pregnant mothers. DEA appears to block the body's ability to absorb the nutrient choline, which is essential for normal development of the brain. Whether the amounts most people absorb from personal care products would cause harm remains unclear. A list of some products that contain DEA can be found at http://householdproducts.nlm.nih.gov/index.htm.

Craciunescu, C.N., Wu, R. & Zeisel, S.H. 2006. Diethanolamine alters neurogenesis and induces apoptosis in fetal mouse hippocampus. FASEB Journal, 20, 1635-1640.

http://www.eurekalert.org/pub_releases/2006-08/uonc-uss080306.php

Lead exposure leads to brain cell loss and damage years later

A study of 532 former employees of a chemical manufacturing plant who had not been exposed to lead for an average of 18 years has found that the higher their lead levels were, the more likely they were to have smaller brain volumes and greater amounts of brain damage. 36% had white matter lesions. The results confirm earlier findings in this same population that people with occupational lead exposure experience declines in their thinking and memory skills years after their exposure.

Stewart, W.F. et al. 2006. Past adult lead exposure is linked to neurodegeneration measured by brain MRI. Neurology, 66, 1476-1484.

http://www.eurekalert.org/pub_releases/2006-05/aaon-lel051806.php

Prenatal exposure to urban air pollutants affects cognitive development

A study of 183 three-year-old children of non-smoking African-American and Dominican women residing in New York City has found that exposure during pregnancy to combustion-related urban air pollutants (specifically, polycyclic aromatic hydrocarbons) was linked to significantly lower scores on mental development tests and more than double the risk of developmental delay at age three.

Perera, F.P. et al. 2006. Effect of Prenatal Exposure to Airborne Polycyclic Aromatic Hydrocarbons on Neurodevelopment in the First Three Years of Life Among Inner-City Children. Environmental Health Perspectives, published online ahead of print.
Full text is available at http://www.ehponline.org/members/2006/9084/9084.pdf

http://www.eurekalert.org/pub_releases/2006-04/cums-iue042506.php

Prenatal exposure to marine toxin causes lasting damage

A rat study has found that a single dose of the naturally occurring marine toxin domoic acid caused subtle but permanent cognitive damage in rats exposed to the chemical before birth. The effect occurred at levels below those generally deemed safe, and suggest that the toxin might negatively affect unborn children at levels that do not cause symptoms in expectant mothers. It was already known that toxic doses of domoic acid can damage the hippocampus.

Levin, E.D., Pizarro, K., Pang, W.G., Harrison, J. & Ramsdell, J.S. 2005. Persisting behavioral consequences of prenatal domoic acid exposure in rats. Neurotoxicology and Teratology, in press.

http://www.eurekalert.org/pub_releases/2005-09/dumc-pet090605.php

Rats infected as newborns vulnerable to memory problems when infected in adulthood

Underscoring the value of good prenatal care, a new rat study has found that rats who experienced a one-time infection as newborns didn't learn as well as adult rats who were not infected as pups, after their immunity was challenged. The findings fit into a growing body of evidence that even a one-time infection can potentially permanently change physiological systems, a phenomenon called "perinatal programming." The findings implicate prenatal infections, as the rats were infected on their 4th day, a time that corresponds, in terms of brain development, with the 3rd trimester in humans. It should be noted that adult rats who were not infected as pups did not suffer memory impairment as the result of adult infection, and those who were infected as newborns were completely normal until they received the second immune system challenge in adulthood. It’s suggested that this phenomenon may help explain some of the individual variability in disease susceptibility.

Bilbo, S.D., Levkoff, L.H., Mahoney, J.H., Watkins, L.R., Rudy, J.W. & Maier, S.F. 2005. Neonatal Infection Induces Memory Impairments Following an Immune Challenge in Adulthood. Behavioral Neuroscience, 119 (1)

http://www.eurekalert.org/pub_releases/2005-02/apa-ria020105.php

Prenatal exposure to solvents associated with negative cognitive effects

A study of 64 children aged 3 to 9 found that those children whose mothers were exposed to organic solvents during their pregnancies had lower scores on certain tests of language, behavior, and cognitive functioning. Organic solvents (used for example in dry cleaning, manufacturing, jobs involving paints and plastic adhesives, nail salons and medical laboratories) are some of the most common sources of workplace chemical exposure reported by pregnant women.

Laslo-Baker, D., Barrera, M., Knittel-Keren, D., Kozer, E., Wolpin, J., Khattak, S., Hackman, R., Rovet, J. & Koren, G. 2004. Child Neurodevelopmental Outcome and Maternal Occupational Exposure to Solvents. Archives of Pediatrics & Adolescent Medicine, 158, 956-961.

http://www.eurekalert.org/pub_releases/2004-10/jaaj-met093004.php

Environmental damage to brains of children

A new report suggests that the brains of children in many parts of Europe are suffering greater damage from environmental risks than previously recognized. A meeting in Malta of European delegates preparing for a ministerial conference on environment and health, being held in Budapest in June, were given preliminary results from a comprehensive study on environmental threats to children's health, being conducted by the WHO and the University of Udine, Italy. The full report is to be published at the Budapest conference. The findings suggest lead is the single most important damaging chemical for children. In 2001, the estimated percentage of European children in urban areas with elevated blood levels (above 10 micrograms per decilitre) ranged from 0.1% to 30.2%.

http://news.bbc.co.uk/1/hi/sci/tech/3568939.stm

Vital role in brain development for the nutrient choline

The nutrient choline is known to play a critical role in memory and brain function by positively affecting the brain's physical development through increased production of stem cells (the parents of brain cells). New research demonstrates that this occurs through the effect of choline on the expression of particular genes. The important finding is that diet during pregnancy turns on or turns off division of stem cells that form the memory areas of the brain. Developing babies get choline from their mothers during pregnancy and from breast milk after they are born. Other foods rich in choline include eggs, meat, peanuts and dietary supplements. Breast milk contains much more of this nutrient than many infant formulas. Choline is a vitamin-like substance that is sometimes treated like B vitamins and folic acid in dietary recommendations.
A choline food database is available at: www.nal.usda.gov/fnic/foodcomp.

Niculescu, M.D., Yamamuro, Y. & Zeisel, S.H. 2004. Choline availability modulates human neuroblastoma cell proliferation and alters the methylation of the promoter region of the cyclin-dependent kinase inhibitor 3 gene. Journal of Neurochemistry, 89 (5), 1252-1259.

http://www.eurekalert.org/pub_releases/2004-03/uonc-sdw031604.php

Prenatal exposure to secondhand smoke associated with greater risk of developmental delay

A new study funded by the National Institute of Environmental Health Sciences has found that children whose mothers are exposed during pregnancy to second-hand smoke have reduced scores on tests of cognitive development at age two, when compared to children from smoke-free homes. In addition, the children exposed to second-hand smoke during pregnancy are approximately twice as likely to have developmental scores below 80, which is indicative of developmental delay. These differences were magnified for children whose mothers lived in inadequate housing or had insufficient food or clothing during pregnancy. The combined effect results in a developmental deficit of about seven points in tests of cognitive performance.

Rauh, V.A., Whyatt, R.M., Garfinkel, R., Andrews, H., Hoepner, L., Reyes, A., Diaz, D., Camann, D. & Perera, F.P. 2004. Developmental effects of exposure to environmental tobacco smoke and material hardship among inner-city children. Neurotoxicology and Teratology, 26 (3), 373-385.

http://www.eurekalert.org/pub_releases/2004-03/nioe-sse031504.php

Pre-term labor drug sensitizes brain to pesticide injury

A rat study has found that unborn rats exposed to terbutaline - a drug commonly prescribed to halt pre-term labor and stave off premature birth - suffered greater brain cell damage than those not given the drug upon secondary exposure to the common insecticide chlorpyrifos. This suggests that this drug might leave the brains of children susceptible to other chemicals ubiquitously present in the environment, and may help explain earlier suggestions that children whose mothers are administered terbutaline suffer cognitive deficits.

Rhodes, M.C., Seidler, F.J., Qiao, D., Tate, C.A., Cousins, M.M. & Slotkin, T.A. 2004. Does pharmacotherapy for preterm labor sensitize the developing brain to environmental neurotoxicants? Cellular and synaptic effects of sequential exposure to terbutaline and chlorpyrifos in neonatal rats. Toxicology and Applied Pharmacology, 195 (2), 203-217.

http://www.eurekalert.org/pub_releases/2004-03/dumc-pld033004.php

Impact of prenatal environment on learning abilities

In a fascinating study that points to the importance of environment (including prenatal environment) in determining behavioral and cognitive abilities, embryos from mice with a low response to stress were transferred to high-stress surrogate mice. The two strains of mice differed not only in their response to stress but also in their learning abilities. At birth, the mice were cross-fostered again and reared by either a low-stress mother or a high-stress mother. The mice were tested at three months, and researchers found that the low-stress mice that were transferred as embryos to and also later reared by high-stress females were less likely to explore new environments than those carried and reared by low-stress mothers. The low-stress mice reared by high-stress surrogates also performed more poorly on cognitive tests of their ability to navigate mazes.

Francis, D.D., Szegda, K., Campbell, G., Martin, W.D. & Insel, T.R. 2003. Epigenetic sources of behavioral differences in mice. Nature Neuroscience, 6 (5),445–446.

http://www.eurekalert.org/pub_releases/2003-05/euhs-ees051203.php

Fetuses recognize mother's voice in the womb

A study of 60 third-term fetuses found that they could distinguish between their mother’s voice and the voice of a stranger, as measured by changes in heart rate. Previous research has shown that newborns prefer their own mother's voice to that of a female stranger, but this demonstrates that this preference and recognition begins in the womb.

Kisilevsky, B.S., Hains, S.M.J., Lee, K., Xie, X., Huang, H., Ye, H.H., Zhang K. & Wang, Z. 2003. Effects of experience on fetal voice recognition. Psychological Science, 14 (3), 220-224(5).

Cognitive development affected in babies exposed prenatally to cocaine

In the first study to use measures of both the mothers’ self report of their prenatal drug use, and infant meconium, which provided a physical measure of the amount of drug exposure, 415 cocaine-exposed infants born in Cleveland were compared to non-exposed infants on cognitive and motor development until age 2. Infants were tested at 6.5, 12 and 24 months. Mental retardation in the cocaine-exposed children at age 2 was 4.89 times higher than would be expected in the general population. The percentage of children with mild delays requiring intervention was almost double the rate of the high risk, non-cocaine group. The study also found that tobacco exposure had significant negative effects on infant development.

Singe, L.T., Arendt, R., Minnes, S., Salvator, A., Kirchner, H.L., Farkas, K., & Kliegman, R. 2002. Cognitive and Motor Outcomes of Cocaine-Exposed Infants. Journal of the American Medical Association, 287,1952-1960.

http://www.eurekalert.org/pub_releases/2002-04/cwru-a2y041602.php

Use of ecstasy during pregnancy may produce learning and memory impairments in child

Researchers today reported the first evidence that a mother’s use of MDMA (ecstasy) during pregnancy may result in specific types of long-term learning and memory impairments in her offspring.
The research was conducted by scientists from Children’s Hospital Research Foundation and the University of Cincinnati College of Medicine, on rats. It appears the damage to offspring occurs only if the drug is taken during a particular critical period of pregnancy.

Broening, H.W., Morford, L.L., Inman-Wood, S.L., Fukumura, M. & Vorhees, C.V. 2001. 3,4-Methylenedioxymethamphetamine (Ecstasy)-Induced Learning and Memory Impairments Depend on the Age of Exposure during Early Development. Journal of Neuroscience, 21, 3228-3235.

http://www.eurekalert.org/pub_releases/2001-04/NIoD-Rfet-2904101.php

Prenatal exposure to Alcohol

Where math takes place normally and in children with fetal alcohol spectrum disorder

An imaging study involving 21 children with fetal alcohol spectrum disorder confirms the importance of the left parietal area for mathematical tasks. Children with FASD are particularly impaired in mathematical ability. Brain activity patterns also revealed that the involvement of regions in the left cerebellum and the brainstem in math processing may be specific to children with FASD.

[291] Lebel C, Rasmussen C, Wyper K, Andrew G, Beaulieu C. Brain Microstructure Is Related to Math Ability in Children With Fetal Alcohol Spectrum Disorder. Alcoholism: Clinical and Experimental Research [Internet]. 2010 ;34(2):354 - 363. Available from: http://dx.doi.org/10.1111/j.1530-0277.2009.01097.x

http://www.eurekalert.org/pub_releases/2009-11/ace-ema111209.php

Possible genetic risk for fetal alcohol disorders

In partial explanation of why children who are exposed to alcohol because their mothers drank during pregnancy are differently affected, new research with rhesus monkeys has found evidence of a gene variant that appears to make the carrier more susceptible to the effects of fetal alcohol exposure. The gene involved is the serotonin transporter gene promoter, and this variant has previously been implicated in increased depression risk.

[499] Kraemer GW, Moore CF, Newman TK, Barr CS, Schneider ML. Moderate Level Fetal Alcohol Exposure and Serotonin Transporter Gene Promoter Polymorphism Affect Neonatal Temperament and Limbic-Hypothalamic-Pituitary-Adrenal Axis Regulation in Monkeys. Biological Psychiatry [Internet]. 2008 ;63(3):317 - 324. Available from: http://www.sciencedirect.com/science/article/B6T4S-4PPNMHP-3/2/0802591581e4061d00d38763b7db6ac6

http://www.eurekalert.org/pub_releases/2007-09/uow-srp092107.php

Post-natal choline supplements may reduce cognitive effects associated with prenatal alcohol exposure

A rat study has found that giving choline to rat pups exposed to alcohol during the equivalent of the third trimester, when there’s a spurt in brain growth, significantly reduced the severity of alcohol-related over-activity and spatial learning deficits. The benefits lasted months after choline treatment, suggesting that choline’s effects are long-lasting. Further studies are needed to establish exactly how choline helps and how late in development it can reduce fetal alcohol effects, and then, whether the effects also apply to humans. However, although early postnatal choline may reduce learning deficits and hyperactivity following early alcohol exposure, it doesn’t help reduce motor coordination deficits.

Thomas, J.D. et al. 2007. Choline Supplementation Following Third-Trimester Equivalent Alcohol Exposure Attenuates Behavioral Alterations in Rats. Behavioral Neuroscience, 121 (1), 120-130.

http://www.eurekalert.org/pub_releases/2007-02/apa-csp022607.php

Eye movement tasks can be used to assess fetal alcohol spectrum disorders

Fetal alcohol spectrum disorders (FASD) cover a wide array of adverse developmental outcomes in children due to prenatal alcohol exposure and is harder to diagnose than the more severe Fetal Alcohol Syndrome. Now new research indicates than simple eye-movement tasks can be used to assess individuals with FASD.

Green, C.R. et al. 2007. Deficits in Eye Movement Control in Children With Fetal Alcohol Spectrum Disorders. Alcoholism: Clinical and Experimental Research, 31 (3), 500–511.

http://www.eurekalert.org/pub_releases/2007-02/ace-emt021507.php

Numbers, sequences pose problems for Fetal Alcohol Syndrome children

An assessment of 50 Canadian children aged six to 15 years, who had been diagnosed with Fetal Alcohol Spectrum Disorder, has revealed that they had specific deficits in memory for numbers and sequences, which may contribute to common math difficulties faced by these children. The study also found differences between Aboriginal children and Caucasian children with FASD.

[1041] Rasmussen C, Horne K, Witol A. Neurobehavioral Functioning in Children with Fetal Alcohol Spectrum Disorder. Child Neuropsychology [Internet]. 2006 ;12(6):453 - 453. Available from: http://www.informaworld.com/10.1080/09297040600646854

http://www.eurekalert.org/pub_releases/2006-12/uoa-nsp122006.php

Prenatal exposure to alcohol linked to lower I.Q.

Analysis of data from the Maternal Health Practices and Child Development Project, an examination of prenatal substance use among women who attended a prenatal clinic from 1983 to 1985, has found that even light to moderate drinking – especially during the second trimester – is associated with lower IQs in African-American offspring at 10 years of age, but not Caucasian children. The difference was not due to differences in the amount or pattern of alcohol use during pregnancy or by differences in socioeconomic status.

[364] Willford J, Leech S, Day N. Moderate prenatal alcohol exposure and cognitive status of children at age 10. Alcoholism, Clinical and Experimental Research [Internet]. 2006 ;30(6):1051 - 1059. Available from: http://www.ncbi.nlm.nih.gov/pubmed/16737465

http://www.eurekalert.org/pub_releases/2006-05/ace-lpa051806.php

New 'eye movement' test may help treat fetal alcohol syndrome

At present there are no objective diagnostic tools that can be used to distinguish between children with Fetal Alcohol Spectrum Disorder (FASD) and those with other developmental disorders such as Attention-Deficit Hyperactivity Disorder (ADHD). Many of the behavioural tests used to assess children with FASD are geared to white, middle-class English-speaking people. Now a pilot study involving 25 children aged 8-12 has found that the specific brain abnormalities associated with FASD can be identified using a simple test that measures eye movement.

Reynolds, J. & Green, C. 2005. Presented at the annual meeting of the international Society for Neuroscience in Washington, D.C.

http://www.eurekalert.org/pub_releases/2005-11/qu-nm111105.php

Key neural system at risk from fetal alcohol exposure

A study of pregnant rhesus monkeys has found that prenatal exposure to alcohol has pronounced effects on the development and function later in life of the brain's dopamine system. Dopamine is a key chemical messenger in the brain. The study indicates there is no safe dose, nor safe time to drink, for pregnant women. The monkeys consumed the equivalent of one to two drinks a day. Abnormalities in dopamine functioning can contribute to addiction, memory, attention and problem solving, and more pronounced conditions such as schizophrenia. The nature of the damage is significantly different depending on the timing of the alcohol exposure.

[511] Kraemer GW, Schneider ML, Moore CF, Barnhart TE, Larson JA, DeJesus OT, Mukherjee J, Nickles RJ, Converse AK, Roberts AD. Moderate-Level Prenatal Alcohol Exposure Alters Striatal Dopamine System Function in Rhesus Monkeys. Alcoholism: Clinical and Experimental Research [Internet]. 2005 ;29(9):1685 - 1697. Available from: http://dx.doi.org/10.1097/01.alc.0000179409.80370.25

http://www.eurekalert.org/pub_releases/2005-09/uow-kns091305.php

Prenatal alcohol exposure can lead to lasting changes in cognitive processing

A study involving 337 African-American children, 7.5 years of age, selected from the Detroit Prenatal Alcohol Longitudinal Cohort, has found that although children known to have been prenatally exposed to moderate-to-heavy levels of alcohol were able to perform as well as other children when tasks were simple – such as naming colors within a timed period – when pressed to respond quickly while having to think about the response, their processing speed slowed down significantly. The observed deficits in working memory are thought to be partly a result of the slower processing speed. The study also confirmed earlier suggestions that number processing is particularly affected.

[946] Burden MJ, Jacobson SW, Jacobson JL. Relation of Prenatal Alcohol Exposure to Cognitive Processing Speed and Efficiency in Childhood. Alcoholism: Clinical and Experimental Research [Internet]. 2005 ;29(8):1473 - 1483. Available from: http://dx.doi.org/10.1097/01.alc.0000175036.34076.a0

http://www.eurekalert.org/pub_releases/2005-08/ace-pae080705.php

Prenatal alcohol exposure has effects far beyond fetal alcohol syndrome

Numerous studies have documented IQ deficits in children with fetal alcohol syndrome (FAS). Little research, however, has found IQ deficits in children with alcohol-related neurodevelopmental disorder (ARND), who generally exhibit less severe neurobehavioral deficits than children with FAS. A new study demonstrates that what was interpreted in prior studies as a lack of any IQ effects in nonsyndromal, alcohol-exposed children was really due to a differential effect of exposure related to several risk/protective factors. Specifically, children whose mothers are older than 30 years, those whose mothers have alcohol dependence, those whose parents provide a less stimulating environment, and those whose mothers reported drinking during the time of conception, are at greater risk from prenatal alcohol exposure.

Jacobson, S.W., Jacobson, J.L., Sokol, R.J., Chiodo, L.M. & Corobana, R. 2004. Maternal Age, Alcohol Abuse History, and Quality of Parenting as Moderators of the Effects of Prenatal Alcohol Exposure on 7.5-Year Intellectual Function. Alcoholism: Clinical & Experimental Research, 28(11), 1732-1745.

http://www.eurekalert.org/pub_releases/2004-11/ace-pae110804.php

New hope for children with fetal alcohol syndrome

A study of 415 people diagnosed with either fetal alcohol syndrome (FAS) or fetal alcohol effect (FAE) found two factors greatly increased the chances of escaping the negative experiences common to those with such problems - being diagnosed early in life and being raised in a stable and nurturing environment. These findings offer hope in a situation that many have regarded as hopeless.

[1051] Streissguth AP, Bookstein FL, Barr HM, Sampson PD, O'Malley K, Young JK. Risk factors for adverse life outcomes in fetal alcohol syndrome and fetal alcohol effects. Journal of Developmental and Behavioral Pediatrics: JDBP [Internet]. 2004 ;25(4):228 - 238. Available from: http://www.ncbi.nlm.nih.gov/pubmed/15308923

http://www.eurekalert.org/pub_releases/2004-08/uow-nhf081004.php

Light drinking during pregnancy may lead to learning and memory deficits in adolescents

The dangers for the developing child of heavy drinking during pregnancy are well-known, but an ongoing longitudinal study of 580 children and their mothers has found that even light to moderate drinking may have significant effects on the cognitive development of the child – effects which show up in adolescents in subtle difficulties with learning and memory, specifically in the auditory/verbal domain.

Willford, J.A., Richardson, G.A., Leech, S.L. & Day, N.L. 2004. Verbal and Visuospatial Learning and Memory Function in Children With Moderate Prenatal Alcohol Exposure. Alcoholism: Clinical & Experimental Research, 28(3), 497-507.

http://www.eurekalert.org/pub_releases/2004-03/ace-ltm030804.php

Deficits associated with prenatal alcohol exposure can be seen as early as infancy

Most of the research on arousal and attention deficits caused by prenatal alcohol exposure has been conducted with children. A new study examined different components of attention through use of heart-rate data collected from six-month-old infants. The findings indicate that slower processing speeds and arousal-regulation problems exist as early as infancy.

Kable, J.A. & Coles, C.D. 2004. The Impact of Prenatal Alcohol Exposure on Neurophysiological Encoding of Environmental Events at Six Months. Alcoholism: Clinical & Experimental Research, 28(3), 489-496.

http://www.eurekalert.org/pub_releases/2004-03/ace-daw030804.php

Prenatal exposure to alcohol affects executive functioning in young children

A study of 316 four-year-old children whose mothers had used various combinations of cocaine, alcohol, and/or marijuana during pregnancy, found that children in the alcohol-exposed group performed significantly worse at an inhibition task than the children in the control group (no maternal use of such substances during pregnancy). This effect persisted even after controlling for prenatal drug exposure, postnatal environmental factors, and child verbal IQ, and suggests that children exposed prenatally to alcohol find it more difficult to inhibit inappropriate behaviors. This may partly explain why such children are at greater risk for social and academic problems. The subtle effect may not be noticeable in most children, but for those who operate at lower levels of functioning, the effect may make all the difference between coping and not. This effect occurred with prenatal alcohol exposure of less than one drink per day. In the United States, it is estimated that among women who know they are pregnant, 2% continue to drink at a moderate level and 5% continue to have at least two drinks per week.

[560] Noland JS, Singer LT, Arendt RE, Minnes S, Short EJ, Bearer CF. Executive Functioning in Preschool-Age Children Prenatally Exposed to Alcohol, Cocaine, and Marijuana. Alcoholism: Clinical and Experimental Research [Internet]. 2003 ;27(4):647 - 656. Available from: http://dx.doi.org/10.1111/j.1530-0277.2003.tb04401.x

http://www.eurekalert.org/pub_releases/2003-04/ace-efi040503.php

Motor skill training may help children with fetal alcohol exposure

The disorders associated with fetal exposure to alcohol are a leading cause of mental retardation and developmental delay.Research with rats has looked at the effect of motor skill training on the development of rats similarly exposed to alcohol at a critical stage of their prenatal development. Those rats trained in increasingly difficult challenges involving motor skills were found to develop 20% more synapses in the cerebellum than the rats that did not train, even though they had the expected 30% loss of Purkinje cells. The research brings hope that, despite the damage done to the motor function, it may be possible to rehabilitate these deficits if caught early enough.

[1369] Klintsova AY, Scamra C, Hoffman M, Napper RMA, Goodlett CR, Greenough WT. Therapeutic effects of complex motor training on motor performance deficits induced by neonatal binge-like alcohol exposure in rats: : II. A quantitative stereological study of synaptic plasticity in female rat cerebellum. Brain Research [Internet]. 2002 ;937(1-2):83 - 93. Available from: http://www.sciencedirect.com/science/article/B6SYR-45H98G8-2/2/f727362f4482126941fb75a2545e6d7a

http://www.eurekalert.org/pub_releases/2002-08/uoia-cpl080702.php

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Abused, neglected children have lower IQ in teens

January, 2011

A large study has found significantly lower IQ in teenagers who have suffered abuse and/or neglect.

An Australian study of 3796 14-year-olds has found that those who had been reported as having suffered abuse or neglect (7.9%) scored the equivalent of some three IQ points lower than those who had not been maltreated, after accounting for a large range of socioeconomic and other factors. Abuse and neglect were independent factors: those who suffered both (and 74% of those who suffered neglect also suffered abuse) were doubly affected.

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New ways of assessing connectivity establish a "brain age" measure of child development

September, 2010

A new way of analyzing brain scans reveals exactly what changes in the brain, in terms of connectivity, as it matures.

Last year I reported on a study involving 210 subjects aged 7 to 31 that found that in contrast to the adult brain, most of the tightest connections in a child's brain are between brain regions that are physically close to each other. As the child grows to adulthood, the brain switches from an organization based on local networks based on physical proximity to long-distance networks based on functionality. Now the same researchers, using five-minute scans from 238 people aged 7 to 30, have looked at nearly 13,000 functional (rather than structural) connections and identified 200 key ones. On the basis of these 200 connections, the brains could be identified as belonging to a child (7-11) or an adult (25-30) with 92% accuracy, and adolescents or adults with 75% accuracy. Moreover, the most important factor in predicting development (accounting for about 68%) was the trimming of the vast number of childhood connections.

Apart from emphasizing the importance of pruning connections in brain development, the main value of this research is in establishing an effective analytic method and baseline measurements for normal development. It is hoped that this will eventually help researchers work out indicators for various developmental disorders.

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Light shed on the cause of the most common learning disability

September, 2010

The discovery that the mutated NF1 gene inhibits working memory through too much GABA in the prefrontal cortex offers hope for an effective therapy for those with the most common learning disability.

Neurofibromatosis type 1 (NF1) is the most common cause of learning disabilities, caused by a mutation in a gene that makes a protein called neurofibromin. Mouse research has now revealed that these mutations are associated with higher levels of the inhibitory neurotransmitter GABA in the medial prefrontal cortex. Brain imaging in humans with NF1 similarly showed reduced activity in the prefrontal cortex when performing a working memory task, with the levels of activity correlating with task performance. It seems, therefore, that this type of learning disability is a result of too much GABA in the prefrontal cortex inhibiting the activity of working memory. Potentially they could be corrected with a drug that normalizes the excess GABA's effect. The researchers are currently studying the effect of the drug lovastatin on NF1 patients.

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New technology can help assess autistic & language disorders

August, 2010

New technology offers hope of early diagnosis of both autism spectrum and language disorders, as well as promising help to parents in assessing the effectiveness of therapy.

A new automated vocal analysis technology can discriminate pre-verbal vocalizations of very young children with autism with 86% accuracy. The LENA™ (Language Environment Analysis) system also differentiated typically developing children and children with autism from children with language delay. The processor fits into the pocket of specially designed children's clothing and records everything the child vocalizes. LENA could not only enable better early diagnosis of autism spectrum disorders, but also allow parents to continue and supplement language enrichment therapy at home and assess their own effectiveness for themselves.

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