Antidepressant linked to developmental brain abnormalities in rodents

A study by researchers at the University of Mississippi Medical Center and the University of California, San Francisco shows that rats given a popularly prescribed antidepressant during development exhibit brain abnormalities and behaviors characteristic of autism spectrum disorders.

The findings suggest that taking a certain class of antidepressants known as selective serotonin reuptake inhibitors – SSRIs – during pregnancy might be one factor contributing to a dramatic rise in these developmental disorders in children.

"We saw behaviors in the treated rats and neurological problems that indicate their brains are not properly conducting and processing information," said Dr. Rick C.S. Lin, professor of neurobiology and anatomical sciences at UMMC and principal investigator on the study.

"However, based on this study alone it would be premature to conclude that a pregnant mother should stop taking SSRIs. A pregnant mother may do more harm to her baby through untreated depression than by taking prescribed SSRIs. This study is a starting point and a lot more research needs to be done."

The study appears online Oct. 24, 2011 in the journal Proceedings of the National Academy of Sciences at www.pnas.org.

The researchers treated more than 200 rats with the SSRI citalopram during key stages of brain development. Rats are born at an earlier developmental stage than humans, equivalent to the end of the sixth month of fetal development in humans.

Most rats received treatment for two weeks, beginning eight days post birth, a neurodevelopment period equivalent to the third trimester and early infancy in humans.

In contrast with control-group rats, the investigators found the treated populations were uninterested in play when young and displayed poor social behaviors as adults. The treated rats also showed abnormal responses to changes in their environment. For example, they froze at the sound of a novel tone and showed little interest in exploring new toys.

"These results demonstrate that rat pups, when exposed perinatally to SSRIs, exhibit behavioral traits often seen in ASD," said Dr. Kimberly Simpson, the paper's first author and UMMC associate professor of neurobiology and anatomical sciences.

Read more: http://www.eurekalert.org/pub_releases/2011-10/uoc--alt102411.php

Pollutants Linked to 450 Percent Increase in Risk of Birth Defects in Rural China

Pesticides and pollutants are related to a 450 percent increase in the risk of spina bifida and anencephaly in rural China, according to scientists at The University of Texas at Austin and Peking University.

Two of the pesticides found in high concentrations in the placentas of affected newborns and stillborn fetuses were endosulfan and lindane. Endosulfan is only now being phased out in the United States for treatment of cotton, potatoes, tomatoes and apples. Lindane was only recently banned in the United States for treatment of barley, corn, oats, rye, sorghum and wheat seeds.

Strong associations were also found between spina bifida and anencephaly and high concentrations of polycyclic aromatic hydrocarbons (PAHs), which are byproducts of burning fossil fuels such as oil and coal. Spina bifida is a defect in which the backbone and spinal canal do not close before birth. Anencephaly is the absence of a large part of the brain and skull.

"Our advanced industrialized societies have unleashed upon us a lot of pollutants," says Richard Finnell, professor of nutritional sciences and director of genomic research at the Dell Children's Medical Center of Central Texas. "We've suspected for a while that some of these pollutants are related to an increase in birth defects, but we haven't always had the evidence to show it. Here we quite clearly showed that the concentration of compounds from pesticides and coal-burning are much higher in the placentas of cases with neural tube defects than in controls."

The study, which was published in August in the Proceedings of the National Academy of Sciences, is the result of a more than decade-long collaboration between Finnell and a team of researchers in Shanxi, a province in northern China.

Finnell sought collaborators in China because the prevalence of neural tube defects is much greater there than it is in the United States. Also, because of its population policies, China is good at tracking births.

"It's an extraordinary natural experiment," says Finnell, who was recently recruited to the university to help anchor the Dell Pediatric Research Institute. "It would be much harder to do this study in the United States, where neural tube defects are more rare. It's also an opportunity to assist the Chinese government in their efforts to lower their birth defect rates."

Read more: http://www.sciencedaily.com/releases/2011/10/111019185134