Sarah Kavanagh and her little brother were looking forward to the bottles of Gatorade they had put in the refrigerator after playing outdoors one hot, humid afternoon last month in Hattiesburg, Miss.
But before she took a sip, Sarah, a dedicated vegetarian, did what she often does and checked the label to make sure no animal products were in the drink. One ingredient, brominated vegetable oil, caught her eye.
“I knew it probably wasn’t from an animal because it had vegetable in the name, but I still wanted to know what it was, so I Googled it,” Ms. Kavanagh said. “A page popped up with a long list of possible side effects, including neurological disorders and altered thyroid hormones. I didn’t expect that.”
She threw the product away and started a petition on Change.org, an online petition platform, that has almost 200,000 signatures. Ms. Kavanagh, 15, hopes her campaign will persuade PepsiCo, Gatorade’s maker, to consider changing the drink’s formulation.
Jeff Dahncke, a spokesman for PepsiCo, noted that brominated vegetable oil had been deemed safe for consumption by federal regulators. “As standard practice, we constantly evaluate our formulas and ingredients to ensure they comply with federal regulations and meet the high quality standards our consumers and athletes expect — from functionality to great taste,” he said in an e-mail.
In fact, about 10 percent of drinks sold in the United States contain brominated vegetable oil, including Mountain Dew, also made by PepsiCo; Powerade, Fanta Orange and Fresca from Coca-Cola; and Squirt and Sunkist Peach Soda, made by the Dr Pepper Snapple Group.
The ingredient is added often to citrus drinks to help keep the fruit flavoring evenly distributed; without it, the flavoring would separate.
The brain has billions of neurons, arranged in complex circuits that allow us to perceive the world, control our movements and make decisions. Deciphering those circuits is critical to understanding how the brain works and what goes wrong in neurological disorders.
MIT neuroscientists have now taken a major step toward that goal. In a new paper appearing in the Aug. 9 issue of Nature, they report that two major classes of brain cells repress neural activity in specific mathematical ways: One type subtracts from overall activation, while the other divides it.
“These are very simple but profound computations,” says Mriganka Sur, the Paul E. Newton Professor of Neuroscience and senior author of the Nature paper. “The major challenge for neuroscience is to conceptualize massive amounts of data into a framework that can be put into the language of computation. It had been a mystery how these different cell types achieve that.”
The findings could help scientists learn more about diseases thought to be caused by imbalances in brain inhibition and excitation, including autism, schizophrenia and bipolar disorder.