Brain Astrocyte Cells (IMAGE) Indiana University Caption The parasite Toxoplasma gondii, which has infected an estimated one in four Americans and even larger numbers worldwide, forms astrocyte in the brain. The parasite can alter important functions within the brain. Credit Indiana University School of Medicine Usage Restrictions None License Licensed content 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.