Optogenetic Control of Reward Circuit (image) NIH/National Institute of Mental Health Caption Fiber optic stimulation mimicking high firing rates (vertical apparatus) of a key reward circuit hub (VTA) instantly converted genetically modified mice resilient to severe social stress into vulnerable animals. High firing rates in the circuit projection from VTA to NAc (and not from VTA to PFC) was found to be the main culprit in triggering depression related behaviors. Blocking the circuit in vulnerable mice instantly made them resilient. Credit Ming-Hu Han, Ph.D., Mount Sinai School of Medicine Usage Restrictions None 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.