Stress During Adolescence Shapes Performance in Adulthood: Context‐Dependent Effects on Foraging and Vigilance

Abstract

Exposure to chronic stress during adolescence can shape behaviour, cognition and physiology in adulthood, but the consequences of these longterm changes remain unclear. Prior studies reporting altered performance following exposure to stress in adolescence have generally interpreted lasting changes as impairments. However, we have recently shown that exposure to chronic unpredictable stress during adolescence (from postnatal days 30-70) can enhance performance in a context-dependent manner during a foraging task. Increases in foraging performance, (previously measured by the number of rewards obtained), are often associated with trade-offs in other behaviours, such as vigilance. Here, we examined the effect of stress exposure in adolescence on adult foraging in male Sprague Dawley rats to determine (1) whether the increase in foraging performance exhibited by animals exposed to stress in adolescence is balanced by a decrease in vigilance, and (2) whether stress in adolescence alters time allocation between foraging and vigilance behaviours in low-and high-threat conditions. We found no evidence of a trade-off between foraging and vigilance; under low-threat conditions, rats exposed to stress in adolescence spent more time being vigilant compared with unstressed rats, suggesting that exposure to stress in adolescence enhances anticipation of threat in adulthood. Under high-threat conditions, adolescentstressed and unstressed rats did not differ in foraging and vigilance behaviours. Given that we have previously found that rats exposed to stress in adolescence nearly double food intake under high-threat, and we now show that high-performing rats do not spend more time foraging, it appears that stress exposure in adolescence may enhance foraging efficiency (food consumed/time) under high-threat conditions rather than time allocation between foraging and competing behaviours. We also examined the relationship, at the level of the individual, between foraging performance and foraging and vigilance behaviours. We found that changes in individual foraging performance between low-and high-threat conditions were independent of behavioural changes (i.e. both highly and poorly performing rats were equally active and contacted a similar number of patches). This suggests that the ability to obtain many rewards under high-threat conditions may be related to efficiency, rather than the frequency of foraging and effort-related behaviours.

Growth patterns in male rats exposed to concurrent long-term environmental challenges

“…It could be an outcome of the stress response elicited by the social instability and crowding, as demonstrated by the reduction of food intake and the size alteration of the zona glomerulosa of the adrenal cortex. Social instability and crowding are recognized environmental stressors (Blanchard et al, 2001;Chaby et al, 2016), while stress is known to alter feeding responses in a bidirectional pattern, with both increases and decreases in intake (Maniam and Morris, 2012).…”

Effects of Trauma in Adulthood and Adolescence on Fear Extinction and Extinction Retention: Advancing Animal Models of Posttraumatic Stress Disorder

“…Animals were left in their home cages and exposed to a scent of a predator, fox urine (Tink’s Fox-P ® ), for 2 h. The scent was sprayed onto cotton balls and encased in a small ventilated plastic container, which was removed at the end of the 2 h (Chaby et al, 2015b ). Following scent exposure, rats were exposed to a recording of predatory feline calls for 20 min in their home cages (Chaby et al, 2015a , b , 2016 ). Finally, animals were placed in an open arena (92 × 92 × 63 cm) for 5 min with a hawk shaped kite hanging overhead, which was lowered towards the rats to mimic approach (Chaby et al, 2015b ).…”

Quitting while you’re ahead: Patch foraging and temporal cognition.

“…This is critical in natural settings (Beauchamp, 2015) and occurs in the laboratory as well (Wallace et al, 2013;Yilmaz & Meister, 2013;Zambetti et al, 2019) Knowing how foraging computations are affected by interruptions may be critical to interpreting foraging decisions. Experiments that program the occurrence of startling events or introduce artificial predators during foraging could examine how these factors interact with foraging decisions (Amir et al, 2015;Chaby et al, 2016;Kim & Jung, 2018;Mobbs et al, 2018;Pellman & Kim, 2016;Walters et al, 2019;Zambetti et al, 2019). Recent years have also seen great advances in computational techniques for identifying statistical structure in animal behavior (Calhoun et al, 2019;Gris et al, 2017;Hsu & Yttri, 2021;McCullough & Goodhill, 2021;Wiltschko et al, 2015).…”