Pluripotent stem cells (IMAGE) Massachusetts Institute of Technology Caption The researchers also used induced pluripotent stem cells to generate forebrain spheroids, which contain neurons and astrocytes. The spheroids grow to two to three millimeters in diameter. Credit Courtesy of the researchers Usage Restrictions Credit must be given to the creator. No derivatives or adaptations of the work are permitted. License CC BY-ND Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.