By: By Tanya Lewis, Staff Writer
Published: 01/27/2014 06:53 AM EST on LiveScience
Using marijuana during pregnancy could affect a baby's brain development by interfering with how brain cells are wired, a new study in mice and human tissue suggests.
Researchers studied marijuana's effects on mice and brain tissue from human fetuses, and found that the active ingredient in marijuana, THC, interferes with the formation of connections between nerve cells in the cerebral cortex, the part of the brain responsible for higher thinking skills and forming memories.
"Our advice is that [pregnant] mothers should avoid marijuana,"said neuroscientist Tibor Harkany of the Karolinska Institute in Sweden, and the Medical University of Vienna, in Austria, who led a study detailed today (Jan. 27) in the EMBO Journal. [11 Facts Every Parent Should Know About Their Baby's Brain]
Harkany added that the effects of prenatal marijuana exposure could even last into adulthood. The drug could have direct effects, or it could sensitize the brain to future drug exposure or neuropsychiatric illnesses.
Previous studies have found that exposure to marijuana during pregnancy can increase a child's risk of having cognitive deficits or psychiatric disorders.
While it is not exactly clear how marijuana may affect the fetal brain at a molecular level, it seems the brain may be particularly sensitive to THC (delta-9-tetrahydrocannabinol) during early development, when neurons are forming critical connections. Any drug that interferes with this development could be detrimental to the child, Harkany said.
In the study, Harkany and his colleagues tested marijuana's effects in three ways: They grew brain cells from mice in the presence of THC, they injected pregnant mice with THC, and they studied the brains of electively aborted human fetuses whose mothers had used marijuana during pregnancy.
The researchers identified a specific protein in nerve cells, called Superior Cervical Ganglion 10 (SCG10), which is essential for normal brain wiring. They found lower levels of this protein in the brains of both human and mouse fetuses exposed to THC compared with individuals who weren't exposed to THC, suggesting that marijuana exposure has a specific effect on the developing brain.
Marijuana and brain development
"Prenatal cannabis disrupts synapses [nerve connections] critical for higher order executive and cognitive function," study researcher Yasmin Hurd, a neuroscientist at Mount Sinai Hospital in New York, told LiveScience in an email.
An increasing number of women of childbearing age are using marijuana, and this group should be made aware of the potential impact on the brain development of their children, she said.
Harkany added that pregnant women should avoid using marijuana use for medical purposes.
Previous long-term studies have shown that children exposed to marijuana in the womb may have an increased risk of showing cognitive effects, seeking out drugs, or having attention deficit disorder, anxiety or depression, according to the study.
Harkany and his colleagues didn't study the effects of marijuana use prior to pregnancy, but he said the drug is cleared from the body in a period days, not months, and using it prior to conception is more likely to affect the likelihood of becoming pregnant than the fetus itself.
So far, Harkany said, no studies have compared the effect of marijuana to that of other drugs, such as alcohol, on fetal brain development.
Follow Tanya Lewis on Twitterand Google+. Follow us @livescience, Facebook& Google+. Original article on LiveScience.
Copyright 2014 LiveScience, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed. ]]>
Our 2024 Coverage Needs You
It's Another Trump-Biden Showdown — And We Need Your Help
The Future Of Democracy Is At Stake
Our 2024 Coverage Needs You
Your Loyalty Means The World To Us
As Americans head to the polls in 2024, the very future of our country is at stake. At HuffPost, we believe that a free press is critical to creating well-informed voters. That's why our journalism is free for everyone, even though other newsrooms retreat behind expensive paywalls.
Our journalists will continue to cover the twists and turns during this historic presidential election. With your help, we'll bring you hard-hitting investigations, well-researched analysis and timely takes you can't find elsewhere. Reporting in this current political climate is a responsibility we do not take lightly, and we thank you for your support.
Contribute as little as $2 to keep our news free for all.
Can't afford to donate? Support HuffPost by creating a free account and log in while you read.
The 2024 election is heating up, and women's rights, health care, voting rights, and the very future of democracy are all at stake. Donald Trump will face Joe Biden in the most consequential vote of our time. And HuffPost will be there, covering every twist and turn. America's future hangs in the balance. Would you consider contributing to support our journalism and keep it free for all during this critical season?
HuffPost believes news should be accessible to everyone, regardless of their ability to pay for it. We rely on readers like you to help fund our work. Any contribution you can make — even as little as $2 — goes directly toward supporting the impactful journalism that we will continue to produce this year. Thank you for being part of our story.
Can't afford to donate? Support HuffPost by creating a free account and log in while you read.
It's official: Donald Trump will face Joe Biden this fall in the presidential election. As we face the most consequential presidential election of our time, HuffPost is committed to bringing you up-to-date, accurate news about the 2024 race. While other outlets have retreated behind paywalls, you can trust our news will stay free.
But we can't do it without your help. Reader funding is one of the key ways we support our newsroom. Would you consider making a donation to help fund our news during this critical time? Your contributions are vital to supporting a free press.
Contribute as little as $2 to keep our journalism free and accessible to all.
Can't afford to donate? Support HuffPost by creating a free account and log in while you read.
As Americans head to the polls in 2024, the very future of our country is at stake. At HuffPost, we believe that a free press is critical to creating well-informed voters. That's why our journalism is free for everyone, even though other newsrooms retreat behind expensive paywalls.
Our journalists will continue to cover the twists and turns during this historic presidential election. With your help, we'll bring you hard-hitting investigations, well-researched analysis and timely takes you can't find elsewhere. Reporting in this current political climate is a responsibility we do not take lightly, and we thank you for your support.
Contribute as little as $2 to keep our news free for all.
Can't afford to donate? Support HuffPost by creating a free account and log in while you read.
Dear HuffPost Reader
Thank you for your past contribution to HuffPost. We are sincerely grateful for readers like you who help us ensure that we can keep our journalism free for everyone.
The stakes are high this year, and our 2024 coverage could use continued support. Would you consider becoming a regular HuffPost contributor?
Dear HuffPost Reader
Thank you for your past contribution to HuffPost. We are sincerely grateful for readers like you who help us ensure that we can keep our journalism free for everyone.
The stakes are high this year, and our 2024 coverage could use continued support. If circumstances have changed since you last contributed, we hope you'll consider contributing to HuffPost once more.
Support HuffPostAlready contributed? Log in to hide these messages.