Exposure to Urine of Canids and Felids, but not of Herbivores, Induces Defensive Behavior in Laboratory Rats

Abstract

Predator odors induce defensive behavior in many prey species. For various reasons, studies carried out up to now have been unable to establish whether predator odor recognition is innate or not. Mostly, only particular odors or wild-living (i.e., experienced) test animals have been used in these studies, restricting the conclusiveness of the observations. In the present study, the behavioral effects of exposure to different predator odors on predator odor-naive laboratory male rats were compared with the effects of different nonpredator odors and of a no-odor control stimulus. Results show that exposure to urine of canids and felids, but not of herbivores or conspecifics, induce defensive behaviors. Taken together, the study provides support for the hypothesis that there is an innate recognition of predator odors in laboratory rats.

In vivo electrophysiological recordings in amygdala subnuclei reveal selective and distinct responses to a behaviorally identified predator odor

“…Cat urine, similar to other utilized predator odors Takahashi et al 2005), reliably elicited defensive responses in rats, characterized by avoidance, increased immobility, risk assessment, and displacement behavior to the odor. High sample variability likely accounts for disparate findings concerning the suitability of cat urine as a predator odor (Blanchard et al 2003;Fendt 2006). However, these and recent reports (Kabitzke and Wiedenmayer 2011;Xu et al 2012) indicate that cat urine is capable of triggering hard-wired defensive responses and, therefore, components of the antipredator neural circuit.…”

“…amygdala; fear; electrophysiology; predator odor; neural responses PREDATOR ODORS are commonly utilized as stimuli in unconditioned tests of fear, as they reliably elicit fear and defensive responses in rodents (Blanchard et al 1998;. Robust fear-related responses have been demonstrated with several odors including cat fur (Blanchard et al 1990), 2,5-dihydro-2,4,5-trimethylthiazoline (a synthetic component of fox feces; Takahashi et al 2005), fox urine (Funk and Amir 2000), and, more recently, lion and coyote urine (Ferrero et al 2011). Studies examining the neural pathway underpinning predator odor-induced fear behavior have flagged the amygdala as playing a central role.…”

Innate or learned acoustic recognition of avian predators in rodents?

“…In contrast to calls in birds, chemical cues in mammals allow for a much more reliable discrimination between predatory and nonpredatory species (Apfelbach et al, 2005;Fendt, 2006). This is due to the direct origin of these odor components from metabolizing meat (Berton et al, 1998).…”

“…Innate recognition of predator olfactory or visual cues has been shown for a diverse range of taxa, including fish (Hawkins et al, 2004), reptiles (Amo et al, 2005;Balderas-Valdivia and Ramírez-Bautista, 2005), birds (Göth, 2004), rodents (Apfelbach et al, 2005) and primates . Interestingly, this innate recognition of predator-related chemical or visual cues is even maintained in laboratory strains of rats and mice that were not exposed to selection pressure from predators for several hundred generations (Blanchard and Blanchard, 1990;Fendt, 2006;Guimaraes-Costa et al, 2007;Wallace and Rosen, 2000;Yang et al, 2004). As one example, our laboratory recently showed that urine samples of feline and canid predators but not of herbivore non-predators induce different species-specific defensive behaviors in predator-naive, laboratory-reared rats (Fendt, 2006).…”

“…Hence, odor-induced defensive behaviors mainly consist of risk assessment behavior and avoidance behavior but to a lesser extent freezing or flight behaviors [cf. discussion in Fendt (Fendt, 2006)]. For predator calls, a recent field study indeed showed that owl playbacks during full moon dramatically reduce the spatial activity of a prey rodent (Schmidt, 2006).…”