Short-term effects of an acute exposure to predatory cues on the spatial working and reference memory performance in a subterranean rodent Matias E. Mastrangelo a, * , Cristian E. Schleich a, b, 1 , Roxana R. Zenuto a, b, 1 a Laboratorio de Ecofisiologı ´a Animal, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Argentina b Consejo Nacional de Investigaciones Cientı ´ficas y Te´cnicas (CONICET), Buenos Aires, Argentina article info Article history: Received 24 August 2008 Initial acceptance 10 October 2008 Final acceptance 18 November 2008 Published online 20 January 2009 MS. number: A08-00555 Keywords: Ctenomys talarum predation reference memory spatial orientation stress subterranean rodent Tala’s tuco-tuco working memory 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 refer- ence 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. Ó 2008 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved. Animals are continually sensing changes in their surroundings. These changes often induce alterations in individuals that put their survival at risk. Exposure to such environmental challenges may threaten an individual’s homeostasis and cause it to be in a stress condition. Factors leading to stress (stressors) can be physical (e.g. infection, hypothermia) or psychological (e.g. predatory exposure, dominant/subordinate interaction) (Reeder & Kramer 2005). The perception of predator’s presence, for instance, induces a set of physiological and behavioural changes in prey species that allow them to maximize their chances of short-term survival. This set of changes in an organism is generalized to a wide variety of stressors and constitutes the stress response (Boonstra 2005; Fletcher & Boonstra 2006). However, not all the responses are consistent across stressors, and the effects vary depending on the kind, extent and level of exposure to that stressor. Although the short-term response is critical for survival, the chronic activation of the hypothalamic–pituitary–adrenal (HPA) axis following repeated exposure is potentially deleterious, affecting long-term survival and fitness through infertility, inhibition of growth and impaired resistance to disease (Sapolsky et al. 2000; Reeder & Kramer 2005). Several studies have examined the effects of stress on spatial learning and memory (Luine et al. 1994a, b; Ohl & Fuchs 1998; Stillman et al. 1998; Diamond et al. 1999; Conrad et al. 2004; Zhao et al. 2004; El Hage et al. 2006). This cognitive function is important for animals to achieve successful foraging, reproduction, territorial defence and avoidance of predators in structurally complex habitats (Kimchi & Terkel 2001). In most of these studies, impairment of spatial learning and memory occurred after the stress exposure (Luine et al. 1994a; Stillman et al. 1998; Diamond et al. 1999; El Hage et al. 2006), although the magnitude and duration of these effects * Correspondence: M. E. Mastrangelo, Laboratorio de Ecofisiologı ´a, Departamento de Biologı ´a, CC 1245, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Funes 3250, Mar del Plata (7600), Argentina. E-mail address: matias_mastrangelo@hotmail.com (M.E. Mastrangelo). 1 C. E. Schleich & R. R. Zenuto are at Laboratorio de Ecofisiologı ´a, Departamento de Biologı ´a, CC 1245, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Funes 3250, Mar del Plata (7600), Argentina. Contents lists available at ScienceDirect Animal Behaviour journal homepage: www.elsevier.com/locate/yanbe 0003-3472/$38.00 Ó 2008 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.anbehav.2008.11.018 Animal Behaviour 77 (2009) 685–692