Short communicationDeciding between conflicting motivations: What mice make of their prefrontal cortex

We investigated the contribution of the mouse prefrontal cortex and, more specifically, the prelimbic area, to a learning task that highlights a choice between two conflicting motivations, the one for food seeking and the one for novelty exploration. We used a learning paradigm in a cross maze task that targets first motivation conflict and second flexible rule adaptation following environmental changes. We show that mice with prelimbic lesions, which showed normal spatial learning, exhibit impairment in switching from one type of reward - food retrieval - to another type - novelty exploration - and sustained difficulties in adapting their behaviour when the rule is changing repeatedly. Mice, like other mammals, possess a prefrontal cortex that participates in the control of the flexible switch between concurrent natural motivations and in the rapid and flexible adaptation to external changes. These results open a way to study in mice models motivation conflict and cognitive adaptation, brain functions known to be compromised in several psychiatric conditions in humans in which the prefrontal cortex functioning is altered.

► Effects of prefrontal cortex lesions in mice were tested on a learning task motivated by food. ► After learning conflict between different motivations (food versus novelty exploration) was tested. ► The mice prefrontal cortex is needed for adaptation to environmental changes but not learning. ► It is also involved in management of conflict between concurrent natural motivations.