Microcircuitry in the Brain (image) University of South Carolina Share Print E-Mail Caption The mu-opioid receptor role in the hippocampal circuit is shown. Credit Adapted from the journal Neuropharmacology. Usage Restrictions Credit the journal Neuropharmacology. Share Print E-Mail 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.