N-methyl-D-aspartate receptors (NMDARs) are glutamate-gated ion channels that play critical roles in neuronal development and nervous system function. Here, we developed a model to study NMDARs in early development in zebrafish, by generating CRISPR-mediated lesions in the NMDAR genes, grin1a and grin1b, which encode the obligatory GluN1 subunits. While receptors containing grin1a or grin1b show high Ca²⁺ permeability, like their mammalian counterpart, grin1a is expressed earlier and more broadly in development than grin1b. Both grin1a^–/– and grin1b^–/– zebrafish are viable. Unlike in rodents, where the grin1 knockout is embryonic lethal, grin1 double-mutant fish (grin1a^–/–; grin1b^–/–), which lack all NMDAR-mediated synaptic transmission, survive until ~10 d dpf (days post fertilization), providing a unique opportunity to explore NMDAR function during development and in generating behaviors. Many behavioral defects in the grin1 double-mutant larvae, including abnormal evoked responses to light and acoustic stimuli, prey-capture deficits, and a failure to habituate to acoustic stimuli, are replicated by short-term treatment with the NMDAR antagonist MK-801, suggesting that they arise from acute effects of compromised NMDAR-mediated transmission. Other defects, however, such as periods of hyperactivity and alterations in place preference, are not phenocopied by MK-801, suggesting a developmental origin. Together, we have developed a unique model to study NMDARs in the developing vertebrate nervous system.

SIGNIFICANCE STATEMENT Rapid communication between cells in the nervous system depends on ion channels that are directly activated by chemical neurotransmitters. One such ligand-gated ion channel, the NMDAR, impacts nearly all forms of nervous system function. It has been challenging, however, to study the prolonged absence of NMDARs in vertebrates, and hence their role in nervous system development, due to experimental limitations. Here, we demonstrate that zebrafish lacking all NMDAR transmission are viable through early development and are capable of a wide range of stereotypic behaviors. As such, this zebrafish model provides a unique opportunity to study the role of NMDAR in the development of the early vertebrate nervous system.

The cats also cross the road an average of 4.5 times in six days, putting themselves in danger

Major League Baseball players and team employees to participate in 10,000-person COVID-19 study

Research suggests bronze blades, thought by some to be too fragile for combat, were deadly weapons across ancient Europe

The researchers gathered data from 166 surveys of insect abundance around the world, mostly conducted since the 1980s

See how researchers at Smithsonian's National Zoo are trying to glean insight into elephant foraging behavior and more.

Alcohol industry groups were successful in getting the Yukon government to pull labels warning of the connection between alcohol and cancer from liquor store shelves, but the strategy may have ultimately backfired, researchers suggest.

In a new twist on oral history, University of Alberta paleontologists have discovered that an Argentinian reptile from 95 million years ago developed a type of tooth enamel that is common in humans and other mammals but rare among reptiles.

A new study facilitated by the Workplace Safety and Insurance Board of Ontario states miners who were forced to inhale an aluminum powder were found to have a higher risk of Parkinson’s disease.

The number of people evaluated for signs of stroke at U.S. hospitals has dropped by nearly 40% during the COVID-19 pandemic, according to a study led by researchers from Washington University School of Medicine in St. Louis who analyzed stroke evaluations at more than 800 hospitals across 49 states and the District of Columbia.

Consumers and companies worldwide have ramped up online ordering for software products and digital goods as they struggle to improve productivity and security while working remotely and spending more time at home. The sharp spike in online commerce aligns with the timing of the current global pandemic. Software-based offerings accounted for the highest levels of growth.

The Coldwater band is calling for federal intervention after Trans Mountain announced it was changing the way it would study the aquifer the First Nation relies on for its drinking water.

A long-term OM worker in North Africa has the opportunity to study the Bible with local friends.

OM EAST is helping meet the need for Bible study booklets to help Bayash Christians grow in their faith.

We visit the KNVB to learn about UEFA's technical exchange initiative.

Before the massive rush to remote learning, most teachers used digital resources as supplements rather than primary materials, a RAND study shows.

When schools reduce racial segregation between schools, racial isolation within the classes inside those schools goes up, according to an analysis of 20 years of North Carolina data.

Court-ordered school desegregation has been more successful in the South than in any other region of the country, but researchers have noted a new threat: the growing number of communities that are seceding from larger school districts to form their own.

When schools reduce racial segregation between schools, racial isolation within the classes inside those schools goes up, according to an analysis of 20 years of North Carolina data.

New findings on a state initiative in Wisconsin suggest that to make the most out of smaller class sizes in the early grades, teachers should focus on basic skills when they have one-on-one contact with students, ask children to discuss and demonstrate what they know, and have a firm, but nurturing,

Keeping preschool class sizes at or under 20 children, and keeping child-teacher ratios at 10 to 1, will work for most children in preschool, according to a new study.

A study of 900 middle schoolers finds that students who report having a sense of belonging both at home and school are less likely to engage in bullying.

There's a new focus on getting more training to early-childhood educators, but there's a dearth of information about what constitutes a high-quality, teacher-preparation program.

Babies as young as 12 months are exposed to nearly an hour a day of screen time, despite warnings from pediatricians to avoid digital media exposure for children under a year and a half, according to a new analysis.

The largest experiment to date comparing commercial math curricula gives a slight edge to two popular programs.

The move to middle school can be a rougher adjustment for students who were high achievers at their elementary schools, finds a new study.

A group of prominent researchers on English-learners is forcefully challenging the findings of a recent working paper that posits that 3rd grade retention was a benefit to struggling English-learners in Florida.

New research suggests that English-language-learner classification has a "direct and negative effect on teachers' perceptions of students' academic skills."

The UEFA Study Group Scheme - through which Europe's national associations exchange technical know-how for European football's well-being - has completed a successful fourth season.

Optimism later in life is protective against a range of health problems. It has commonly been a focus in adolescent mental health promotion. Cross-sectional studies suggest a protective effect against adolescent health risks, but prospective studies have been lacking.

Optimism is somewhat protective against adolescent health risks; the strongest effect was seen against the onset of new depressive symptoms. Its protective effect against heavier substance use and antisocial behavior was modest and only for the highest categories compared to the lowest. Promoting optimism along with other positive aspects of psychological and emotional style has a role in mental health promotion that is likely to be enhanced if an intervention also addresses risk and protective factors in an adolescent's social context. (Read the full article)

Several correlational studies documented that participants who would be classified as "pathological" video gamers demonstrate a pattern of correlations with other variables that are comorbid (eg, depression) or occur with (eg, poorer grades and increased hostility) other addictions.

Following a large sample across 2 years, this study provides needed data on risk factors for becoming a pathological gamer, how long pathological gaming lasts, outcomes, and whether it is a primary problem or is a symptom of comorbid problems. (Read the full article)

The National Children's Study, a large-scale, longitudinal, birth cohort study of US children that endeavors to identify preventable and environmental origins of chronic diseases, has begun recruitment.

In a highly diverse, urban setting, pregnant women can be recruited to participate in the National Children's Study at rates similar to those obtained in clinic settings. Refinements to the pregnancy screener and other components are needed to optimize implementation. (Read the full article)

Adults born at very low birth weight (VLBW) (<1.5 kg) have higher blood pressure and higher fasting insulin levels than their peers born at term. However, they show no signs of endothelial dysfunction in childhood and in adolescence.

Adults born at a VLBW showed no endothelial dysfunction compared with term adults. They had, however, a thicker intima-media layer in relation to lumen size. More rapid growth during their first weeks of life was associated with better endothelial function. (Read the full article)

Educators, public health authorities, and law enforcement are confronting an increasing number of cases in which youth made sexual images of themselves and other minors and transmitted them via cell phones and the Internet.

This study provides the first detailed and comprehensive national estimate of the percentage of youth who create and distribute various kinds of sexual images. (Read the full article)

Over 500 000 children in the United States sustain a traumatic brain injury (TBI) each year. Headaches are commonly reported after TBI in adults, but little is known about the epidemiology of headache after pediatric TBI.

Headaches are more common 3 months after pediatric TBI than after arm injury. The frequency of headache after TBI is related to patient gender, age, and injury severity. Headaches after mild TBI were most common among girls and teenagers. (Read the full article)

Two UK models predict the risk of mortality in very preterm Western infants (1) alive at onset of labor and (2) admitted for neonatal intensive care. Prognostic models need temporal and geographic validation to evaluate their performance.

The 2 models showed very good performance in a recent large cohort of very preterm infants born in another Western country. The accurate performance of both models suggests application in clinical practice (Read the full article)

Childhood UV light exposures, specifically sunburns, have been shown to be associated with melanoma development later in life.

To date, most studies in this age group have been cross sectional in nature. This is the first prospective study of sunburn and sun behaviors in this age group. (Read the full article)

Candidate genes involved in thrombophilia, inflammation, and preterm birth have previously been associated with cerebral palsy. Most studies to date have included small cohorts, did not allow for multiple testing, and require replication.

This study of children with cerebral palsy and their mothers did not confirm previously reported candidate gene associations. Prothrombin gene mutation was associated with hemiplegia in children born at term to mothers with a reported infection during pregnancy. (Read the full article)

The demographics of trials that use antenatal consent may not be representative of the populations that they are intended to study.

This study analyzes the difference in clinical outcomes between the enrolled and eligible but not enrolled populations of a trial that required antenatal consent. (Read the full article)

Changes in BMI category appear to be common in young children and are associated with cardiometabolic risk in cross-sectional studies. However, there are few longitudinal studies and little information from multiethnic samples of US middle school children.

Findings demonstrate that shifts in BMI category are common in middle-school-aged children and associated with clinically meaningful changes in cardiometabolic risk factors. Programs to promote decreases in BMI, prevent increases, and moderate risk are indicated. (Read the full article)

Fetus and infants until 3 months of age are unable to metabolize caffeine, which crosses the placenta and in adults has a somnolytic effect. Little is known about the effect of caffeine consumption by pregnant or nursing mothers over infant sleeping.

In this setting where caffeine is largely consumed in pregnancy and by nursing mothers, heavy consumption (≥300 mg/day) did not increase the number of nighttime awakenings by their 3-month-old infants. (Read the full article)

Cancer in a child may affect the quality of the parents’ relationship, but few studies have examined a potential effect on parental divorce, and no studies have accounted for the proportion of couples that live outside formal marriages.

In this nationwide registry-based study with up to 20 years of follow-up, we included both married and cohabiting couples, reflecting modern family structures. We found that experiencing cancer in a child is not a risk factor for the parents separating. (Read the full article)

We know that many evidence-based treatments for acute asthma are underused, and adherence with treatment guidelines is poor; however, studies have focused on β₂ agonists and corticosteroids, but little is known about intravenous magnesium, which has substantial evidence of benefit.

Magnesium is used infrequently in Canadian pediatric emergency departments in hospitalized children with acute asthma, with variation across sites. More than half of this population does not receive frequent bronchodilators and timely corticosteroids. (Read the full article)

Conflicting results exist concerning long-term outcome in healthy infants with metabolic acidosis at birth.

Neonates who appear well after perinatal metabolic acidosis do not have an increased risk of neurologic or behavioral problems in need of referral actions or pedagogic arrangements at the age of 6.5 years. (Read the full article)

More than one-tenth pediatric patients use complementary and alternative medicines (CAM) for their medial conditions in the United States. Traditional Chinese medicine (TCM) is the most commonly used CAM in East Asia but large-scale epidemiologic studies are lacking.

In comparing TCM and non-TCM users among children in Taiwan, children’s age and parental TCM use were strongly associated with TCM use. Additionally, dyspepsia and allergic rhinitis were positively related to increasing TCM use. (Read the full article)

Survival of children born with Down syndrome has been improving, but few studies have used population-based data to examine the influence of fetal and maternal characteristics on survival.

This study examined predictors of survival for children born with Down syndrome using population-based data from the UK Northern Congenital Abnormality Survey and shows that year of birth, gestational age, birth weight, and presence of additional anomalies influence survival status. (Read the full article)

Children with specific language impairment are at risk for social difficulties. However, whether this occurs adaptively as a result of language impairment or occurs as a result of an underlying deficit in social cognition remains unclear.

We used eye tracking to explore how children with specific language impairment view social scenes. The overall gaze behavior resembled that of typically developing children. Significant attention to the speaker’s mouth may result in receiving less social-emotional information from the eyes. (Read the full article)

Although obesity is correlated with levels of systolic and diastolic blood pressure, there is little evidence if the increases in obesity over the last 40 years have resulted in increased blood pressure levels.

Despite increases in obesity in Bogalusa, Louisiana between 1974 and 1993, there was no increase in systolic or diastolic blood pressure levels. It should not be assumed that trends in high blood pressure have paralleled those for obesity. (Read the full article)

Infant malnutrition is known to be associated with behavioral and cognitive impairment throughout childhood, adolescence, and young adulthood. However, controlled studies addressing adult outcomes in middle life, including earning potential, educational attainment, and standard of living, are limited.

A discrete episode of moderate to severe malnutrition in infancy, with good rehabilitation thereafter, is associated with lower adult social status and a widening income gap relative to healthy controls, partially attributable to cognitive impairment in the previously malnourished. (Read the full article)