Defensive antinociception and antipredatory responses in prey threatened by distinct odoriferous cues from Felis silvestris catus.

Fear, an adaptive response to danger situation, is vital for the survival of both human beings and rodents. Predator odor-related cues and contextual fear work as valuable models for studying neurobiological circuits, providing insights into unconditioned and conditioned fear-related behavioral and physiological responses, including fear-related antinociception. This study investigated whether a fear paradigm based on predator odor cues could trigger the defensive antinociceptive phenomenon. Our findings indicate that while both the exposure to different predator odor cues and the re-exposure to the experimental context elicit similar defensive behaviors, such as the head-out response (an inhibitory avoidance behavior), only the exposure to the predator odor cues induced defensive antinociception. Notably, during the re-exposure to the experimental context, the endogenous pain modulatory system is not recruited, suggesting that defensive antinociception is not universally elicited by all fear-related reactions. Instead, defensive antinociception appears to be modulated by distinct neural circuits and olfactory perception-dependent mechanisms that adjust dynamically according to threat imminence. Thus, antinociception emerges as part of the immediate defensive response to a threatening odor cue, rather than as a consequence of fear memory retrieval. (PsycInfo Database Record (c) 2026 APA, all rights reserved).