Neurons in the Auditory Cortex (image) Johns Hopkins Medicine Share Print E-Mail Caption This is a two-photon microscopy image showing a calcium sensor (green), the nuclei of neurons (red) and supporting cells called astrocytes (magenta). Credit John Issa/Johns Hopkins Medicine Usage Restrictions Credit required. 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.