Glutamatergic mechanisms of the dorsal periaqueductal gray matter modulate the expression of conditioned freezing and fear-potentiated startle

► dPAG glutamatergic mechanisms modulate the expression of conditioned fear. ► Intra-dPAG injections of glutamatergic agonists enhance conditioned fear. ► Glutamatergic antagonist reverts the agonists effects on conditioned fear. ► FPS does not follow a monotonic relation with conditioned freezing.