Pathway of an Electrode in the Brain (IMAGE) Heidelberg University Hospital Caption The habenula is a tiny double structure in the diencephalon. For stimulation two electrodes are implanted. The picture shows the pathway of an electrode in the brain. Credit Source: Heidelberg University Hospital. 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.