Investigating the roles of prefrontal cortex in the regulation of anxiety-like behaviors in mice, using in vivo microdialysis technique

Abstract

We investigated the possible roles of the prelimbic (PL) and infralimbic (IL) prefrontal cortex in the regulation of anxiety-like behaviors by pharmacologically activation with a sodium channel activator veratrine. The extracellular glutamate levels were measured by in vivo microdialysis and the behaviors were assessed in the open field test in mice, simultaneously. The extracellular glutamate levels rose significantly after perfusion of veratrine in the IL and PL. Interestingly, the PL, but not IL, activation produced anxiety-like behaviors in mice. The local co-perfusion of a NMDA receptor antagonist MK-801 in the PL completely diminished the behavioral changes, without any effects on the veratrine-induced elevated extracellular glutamate levels. These results suggested that although the IL is adjacent to the PL, these two regions have differential functions in the expression of anxiety-like behaviors, and also the activation of the PL induces the anxiety-like behaviors via glutamatergic neurotransmission in mice.