Spatiotemporally distinct dopamine domains in the hippocampus

The hippocampus is necessary for forming long-term memories and the neuromodulator dopamine is critical in this process. Exactly how dopamine acts in the hippocampus remains opaque since there is no clear picture of when and where dopamine is released. Using newly developed optical dopamine sensors, we find that hippocampal dopamine release is split into two distinct spatial domains. In Pavlovian conditioning, the "deep" domain shows dopamine transients that largely correspond to actions used to consume rewards, while in a goal directed task, dopamine ramping appears in both domains during reward approach. Notably, distinct domains were initially absent and developed over experience. Our results reveal specific dopamine dynamics that are likely to play distinct and dissociable roles during behavior.