Determining the biological associates of acute cold pressor post-encoding stress effects on human memory: The role of salivary interleukin-1?.

ABSTRACT: Stress generally hurts many aspects of memory, but an interesting finding to emerge from the stress and memory literature is that stress that occurs shortly after learning (i.e., post-encoding stress) usually benefits memory. Although this effect is well established, the biological mechanisms underpinning this effect are not-especially in humans. We addressed this gap in the present study by collecting saliva samples from 80 participants who were randomized to a post-encoding stress (i.e., cold pressor for 3?min) or control task (i.e., warm water for 3?min) and 48?h later completed a recognition memory task. Saliva was collected both prior to and 15?min after the offset of (18?min after the onset of) the stress/control manipulation. Drawing on animal and human work, we examined how five stress-responsive biomarkers-cortisol, salivary ?-amylase, progesterone, estradiol, and the proinflammatory cytokine interleukin (IL)-1?, all assessed in saliva-related to the effects of stress on memory. We found that stress enhanced recollection of negative images and that these effects were selectively related to salivary IL-1?. Moreover, we found that the beneficial effects of stress on memory were statistically mediated by salivary IL-1?. We found no robust associations-either linear or quadratic-between memory and any other biomarker, nor did we find significant interactions between biomarkers in predicting memory. These results suggest that immune system activity indexed by salivary IL-1? may play an important role in contributing to post-encoding stress effects on human memory.

SUBMITTER: Shields GS 

PROVIDER: S-EPMC6754786 | biostudies-literature | 2019 Oct

REPOSITORIES: biostudies-literature