eLife assessment
This is an important study that characterized the activity of optogenetically identified dopaminergic and GABAergic neurons in the ventral tegmental area (VTA) in mice performing a memory-guided T-maze task. The authors show that subpopulations of dopaminergic and GABAergic neurons exhibited choice-related activity during the delay period, which was enhanced when the task requires short-term memory. The reviewers found that the results are surprising, novel, and convincing, while some relatively minor issues were pointed out regarding the data presentation and analysis.