Nervous System Activity in Lymphnode (IMAGE) Cell Press Caption This image shows lymphocytes (purple) amongst blood vessels (orange), and the calcium signalling (green) that results from noradrenaline neurotransmitter release and causes immune cells to stop moving Credit Scott Mueller Usage Restrictions credit required 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.