The Environmental Factor – March 2020: Experts say the environment affects brain development

Funded by NIEHS Center for Human Health and the Environment (CHHE) at North Carolina State University (NCSU) held its fourth annual scientific symposium titled “Brain-Environment Interactions” on February 20. Academic researchers, government scientists, postdoctoral interns, undergraduate and graduate students met to listen, learn and share their latest findings.

Too many chemicals, not enough time

“It could take up to a decade for the pesticide to be proven to be neurotoxic, and in the meantime, susceptible populations are being exposed,” Biehl said. (Photo courtesy of Jesse Saffron)

“There has been an astonishing rise in neurodevelopmental disorders in the United States and the world,” National Toxicology Program (NTP) toxicologist Mamta Behl, Ph.D., noted during her keynote address. “At NTP, we ask what could be some of the environmental causes.”

She cited evidence showing an increased prevalence of conditions such as Attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder. It drew attention to industrial and commercial chemicals, such as pesticides and flame retardants.

“There are tens of thousands of compounds in our environment that have yet to be tested,” she explained. “Children and pregnant women are exposed, and this is a real problem.”

Conventional animal studies can be expensive and time-consuming, and impractical due to the number of chemicals on the market. Therefore, there is a demand for better tools for analyzing such materials, says Biehl.

new trend

“The NTP recently established an innovative Developmental Health Effects of Neurotoxicity Program, recognizing the need for a new framework for evaluating chemicals with potential neurodevelopmental effects,” she said.

One goal is to quickly arrange vehicles for in-depth testing. For this, researchers can use screening methods such as cell models, animal models that use zebrafish, or other alternatives to rodent tests.

Renowned geneticist Randy Gertel, Ph.D., from NCSU, was an active participant during the symposium. (Photo courtesy of Jesse Saffron)

The program aims to promote collaboration and data sharing between toxicologists in the United States and abroad, and to train young scientists in new methods. Biehl said she is particularly interested in working more with health care providers.

“Right now, there’s not much communication,” she said. “We’re trying to change that by understanding the concerns in the clinic and how we can help translate the research.”

Early exposure to air pollution, BPA

The CHHE seminar featured nine other speakers and 24 poster presentations. Some of the topics covered included:

• How environmental factors may contribute to amyotrophic lateral sclerosis, or ALS.
• Developmental exposure to air pollution and maternal stress.
• Flame retardants and social and emotional behaviour.

NCSU epidemiologist Kathryn Hoyo discusses the genetic changes associated with Alzheimer’s disease. (Photo courtesy of Jesse Saffron)

NIEHS Beneficiary Janis Juraska, Ph.D.D., of the University of Illinois, gave a keynote speech on her work investigating the effects of bisphenol A (BPA) and phthalates, chemicals found in many plastics, on the medial prefrontal cortex.

In humans, [that area of the brain] “Very important for every neurobehavioral problem that exists,” Jurasca said.

Take autism as an example. In young males with this disorder, the medial prefrontal cortex shows an increase in neurons. Juraska’s team found that in male rats, developmental exposure to BPA led to such a rise. However, she made clear that she was not linking the chemical to autism – more work is needed on the underlying biological mechanisms.

on the border

Patricia Jensen, PhD, chair of the NIEHS Developmental Neurobiology Group, concluded the meeting.

Last year, the National Institutes of Health awarded Jensen the position unanimously. Check out The Environmental Factor’s story to learn more about her research. (Photo courtesy of Jesse Saffron)

“My lab focuses on the central noradrenaline system — the cells within the brain and peripheral nervous system that actively make noradrenaline,” Jensen said.

Noradrenergic neurons release norepinephrine in areas of the brain that affect attention, learning, sleep, and other key functions. Jensen discussed locus coeruleus, an important part of the central noradrenergic system.

“One of the big questions we have is what are the long-term effects of the change in the norepinephrine signaling locus during development,” she said.

So far, her lab has found that in male mice, early loss of such signals leads to seizures, reduced social communication, learning deficits, and other traits associated with developmental disorders. From now on, Jensen will examine chlorpyrifos, a common insecticide. Its aim is to determine whether early exposure to chlorpyrifos causes long-term changes in the function of noradrenergic neurons in the blue locus.

Samir Nasser, a post-baccalaureate fellow at the NIEHS Basic Neurobehavioral Laboratory, answered questions about his recent research. (Photo courtesy of Jesse Saffron)

“This is one of the most important frontiers of research in environmental health – to understanding how environmental stressors affect brain development and function, and lead to cognitive, neurodegenerative and behavioral outcomes,” CHHE Director Rob Smart told attendees.

(Jesse Saffron, JD, is a writer and technical editor in the NIEHS Office of Communications and Public Communications.)

from San Jose News Bulletin https://sjnewsbulletin.com/the-environmental-factor-march-2020-experts-say-the-environment-affects-brain-development/