The Role of the Ventral Dentate Gyrus in Learned Approach-Avoidance Conflict Resolution

Approach-avoidance conflicts occur when organisms face stimuli linked to opposing affective outcomes, and must choose to either engage or disengage. It is increasingly acknowledged that the hippocampus, particularly its ventral aspect, is part of a critical network involved in recognizing and resolving approach-avoidance conflicts. Less is known about how the ventral hippocampusâ subdivisions along its transverse axis mediate affective conflicts. Using transient pharmacological lesions in Long-Evans rats, the present study observed that temporary inactivation of the ventral dentate gyrus resulted in an increased bias towards approaching affectively conflicting information, despite also being associated with aversive outcomes. Further testing showed that this could not be explained by an increased bias towards either positive or negative information alone, and was only observed when the conflicting stimuli were presented together. These findings suggest that the ventral dentate gyrus is a critical actor in resolving learned approach-avoidance conflicts.M.A