C4 At Synapses (IMAGE) Broad Institute of MIT and Harvard Caption Imaging studies showed C4 (in green) located at the synapses of primary human neurons. Image courtesy of Heather de Rivera (McCarroll lab). Credit Image courtesy of Broad Institute 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.