Short-term effects of an acute exposure to predatory cues on the spatial working and reference memory performance in a subterranean rodent

Spatial memory is important for animals to achieve successful foraging, reproduction, territorial defence and predator avoidance in structurally complex habitats. This cognitive function has been shown to be affected under stress conditions in surface-dwelling rodents. Here we used the Tala's tuco-tuco, Ctenomys talarum, a subterranean rodent that inhabits complex burrow systems, as a study model. This species has a highly developed spatial ability and individuals are regularly exposed to predatory stress while foraging on the surface. We examined the consequences of a single and brief exposure to predatory cues on the spatial working and reference memory performance. We trained wild-caught individuals (32 males, 36 females) in a six-arm radial maze (spatial working memory task) or a longitudinal maze (spatial reference memory task). Once the animals reached a memory performance criterion, they were exposed to a direct predatory cue (immobilization), an indirect predatory cue (cat urine odour) or both cues combined, and their memory performance was evaluated. Exposure to direct and combined predatory cues impaired spatial reference memory, increasing both the latency to achieve the goal and the number of errors during the test. Combined presentation of both predatory cues also negatively affected spatial working memory, but only for latency to achieve the goal. Our results suggest that use of spatial working memory during a predatory attack on the surface allows C. talarum to relocate burrow entries rapidly and hence increases survival probabilities.