Dombeck Dopamine Axon (VIDEO) Northwestern University This video is under embargo. Please login to access this video. Caption This movie shows rapid signaling dynamics in dopamine axons that have never before been observed in a brain. Each thin orange fiber is an individual dopamine axon, approximately 1 micrometer in diameter. The movie was captured using a powerful new imaging technique. Credit Northwestern University Usage Restrictions Must use credit 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.