Ventral hippocampus and the contextual control of Pavlovian and instrumental behaviors.

The purpose of the present review is to consider and integrate research that has examined the role of the ventral hippocampus (VH) in the contextual regulation of both Pavlovian and instrumental behaviors. To do so, we selectively review research on the role of the VH in the extinction and renewal of Pavlovian fear conditioning, as well as its contribution to the learning and performance of appetitive instrumental responding. We emphasize that "contexts" can function in several ways to control behavior. Our review suggests that, across both paradigms, the VH contributes to several forms of contextual regulation. The evidence further indicates that these context effects depend on interactions between the VH and medial prefrontal cortex, suggesting a shared hippocampal-prefrontal circuit that supports contextual control. We also consider how these functions relate to broader hippocampal organization, drawing on evidence that while the dorsal hippocampus preferentially encodes discrete spatial information, the VH may be especially important for integrating salient contextual information across experience, particularly under conditions of ambiguity. Together, the evidence suggests that the VH plays a common and essential role in enabling contextual information to guide both Pavlovian and instrumental behaviors.