Meeting Abstract

62.6  Sunday, Jan. 5 14:45  Examination of the effects of physiological stress and cortisol levels on the acquisition of long-term declarative memories VANESSA NEUTZLER, VP*; PALOMA REINOSO, P; St. Edward’s University; St. Edward’s University vneutzl@stedwards.edu

Previous studies have indicated an effect of stress on learning, however, the relationship between stress, stress hormones and memory in humans has yet to be fully elucidated. The hippocampus is required for declarative memory consolidation, and studies suggest that cortisol, a steroid stress hormone which crosses the blood-brain-barrier, binding to glucocorticoid receptors in the hippocampus, may negatively impact learning. The present study examines the effect of stress-induced endogenous cortisol release on the acquisition of long-term declarative memories in humans. Experiments were conducted from 1:30- 4:30 p.m., to offset fluctuations in cortisol levels normally seen in the morning. Male and female subjects (n= 54, age 18-24 yrs) were asked to engage in memory acquisition and retrieval tasks, while experiencing a stressful or neutral (control) stimulus. To induce stress the socially evaluated cold-pressor stress test was used, with a room temperature water bath as control. Physiological indicators of stress were monitored throughout, and saliva samples were gathered before and during memory consolidation. Memory performance was assessed by free recall 24h later. An enzyme-linked immunosorbent assay (ELISA) was used for the quantitative analysis of salivary cortisol. Memory performance and physiological vitals were analyzed. Physiological stress induction was confirmed, as cortisol levels increased and heart rate was found to be significantly higher than baseline in stressed subjects. Data indicates decreased memory performance in stressed subjects compared to controls.