Short-term anxiety response of the subterranean rodent Ctenomys talarum to odors from a predator

Abstract

Prey organisms exhibit primary adaptations that contribute to avoid predators and secondary mechanisms that allowthemto defend themselves. Particularly behavioral adaptations allowthem to recognize, avoid and defend against predators. Facing a predatory risk, anxiety is a reaction of adaptive value, assessing the potential risk of this encounter as well as generating an autonomic and behavioral response that would help resolve that situation. Concomitantly, a stressful condition could result according to intensity and length of exposure. Previous studies in the subterranean rodent Ctenomys talarum revealed that exposure to direct cues of the presence of a predator has negative effects on learning and spatial memory. These impairments in their cognitive abilities could be avoided by the development of defensive anti-predatory behaviors. Thus, in this study we evaluated the behavioral and physiological responses of C. talarumto odors derived frompredators (urine and fur of domestic cat) used as indicators of potential risk of predation. In the open field, exposure to odors from a predator induced a decrease in time moving with respect to control (not exposed) individuals, as well as an increase in the time scratching the walls near and far from the odor source. In the elevated plus maze, exposed individuals walked shorter distances, entered less frequently and remained less time scratching the walls in transparent arms. Physiological parameters did not show differential variations among treatments in both tests utilized. The results shows that exposure of the tuco-tuco to odors of a predator generates a state of anxiety and induces behavioral changes associated with decreased locomotor activity and avoidance behavior generation.