Survival Decision Making

Abstract

All animals must make decisions in order to survive. Prey animals especially must not only forage for food, but avoid predators and if fortunate enough to survive a predator encounter, learn how to survive in the future. Over time, the rat has evolved to maximize the exploitation of resources in its environment and quickly adapt to its surroundings, making it the most successful mammal on the planet. In doing so, they have acquired many innate behavioral responses to different stimuli in their environment and possess exceptional spatial memory. Translational fear and avoidance research for clinical disorders in humans owes much to rodent research on the topic, but restricts the full behavioral repertoire of the rat through limited behavioral paradigms like fear conditioning. This dissertation explores the natural foraging behaviors of the rat in the laboratory, brain areas implicated in naturalistic predator avoidance, and the ability of rats to use information about a predator attack to survive in the future. The first study compared the fear responses to various types of 2D and 3D looming aerial stimulus threats. This study also includes the inactivation of the basolateral amygdala and superior colliculus and how they are required for eliciting innate fear responses to aerial threat. The results show a drastic increase in fear to a 3D aerial predator threat than a 2D threat, and also found significant sex differences with females taking longer to habituate to overhead fear-inducing stimuli. The second study focuses on the utility of Pavlovian fear conditioning in a naturalistic environment and what cues or information rats will use after surviving a predator attack. Here rats that have undergone a pairing of shock and tone while foraging, continue to forage unimpeded when that tone is played again. Alternatively, pairing a shock with a predator attack lead to an enhanced fear of the foraging context and to a novel tone played within this context. This more adaptive sensitization process is better utilized in a natural setting than traditional cue-based fear conditioning because it would not require the learning of discrete tones to avoid a predator attack.