Predation is considered a major selective pressure in the evolution of fear, but the neurophysiology of predatorinduced fear is unknown. We simultaneously recorded lateral amygdala (LA) and prelimbic (PL) area neuronal activities as rats exited a safe nest to search for food in an open space before, during, and after encountering a "predator" robot programmed to surge from afar. Distinct populations of LA neurons transiently increased spiking as rats either advanced or fled the robot, whereas PL neurons showed longer-lasting spike trains that preceded and persisted beyond LA activity. Moreover, discrete LA-PL cell pairs displayed correlated firings only when the animals either approached or fled the robot. These results suggest a general fear function of the LA-PL circuit where the PL participates in the initial detection of potential threats, the LA signals the occurrence of real threats, and the dynamic LA-PL interaction optimizes defensive readiness for action.