Almost every human cell teems with a potpourri of tiny powerhouses: mitochondria. Up to thousands of them. These organelles use oxygen to convert the nutrients from the food you eat into a form of energy the body can use. The brain consumes a lot of this energy — about 20 percent. Could changes in mitochondria, then, affect how the brain functions and contribute to autism? Read the related article, Meet the ‘mitomaniacs’ who say mitochondria matter in autism.