Learning Under Stress: The Inverted-U-Shape Function Revisited

Autor/inn/en	Salehi, Basira; Cordero, M. Isabel; Sandi, Carmen
Titel	Learning Under Stress: The Inverted-U-Shape Function Revisited
Quelle	In: Learning & Memory, 17 (2010) 10, S.522-530 (9 Seiten) PDF als Volltext Verfügbarkeit
Sprache	englisch
Dokumenttyp	gedruckt; online; Zeitschriftenaufsatz
ISSN	1072-0502
DOI	10.1101/lm.1914110
Schlagwörter	Memory; Animals; Learning Processes; Stress Variables; Task Analysis; Brain Hemisphere Functions; Biochemistry; Tests; Recall (Psychology); Training; Individual Differences; Personality; Profiles + Suchen Sie Ihr Suchwort? Gedächtnis; Animal; Tier; Tiere; Learning process; Lernprozess; Aufgabenanalyse; Biochemie; Examination; Prüfung; Examen; Abberufung; Ausbildung; Individueller Unterschied; Personalität; Charakterisierung; Profilanalyse
Abstract	Although the relationship between stress intensity and memory function is generally believed to follow an inverted-U-shaped curve, strikingly this phenomenon has not been demonstrated under the same experimental conditions. We investigated this phenomenon for rats' performance in a hippocampus-dependent learning task, the radial arm water maze (RAWM). Variations in stress intensity were induced using different water temperatures (25[degrees Celsius], 19[degrees Celsius], and 16[degrees Celsius]), which elicited increased plasma corticosterone levels. During spatial training over three consecutive days, an inverted-U shape was found, with animals trained at 19[degrees Celsius] making fewer errors than animals trained at either higher (16[degrees Celsius]) or lower (25[degrees Celsius]) stress conditions. Interestingly, this function was already observed by the last trial of day 1 and maintained on the first day trial of day 2. A long-term recall probe test administered under equal temperature conditions (20[degrees Celsius]) revealed differences in performance according to the animals' former training conditions; i.e., platform searching for rats trained at 25[degrees Celsius] was less accurate than for rats trained at either 16[degrees Celsius] or 19[degrees Celsius]. In reversal learning, groups trained at both 19[degrees Celsius] and 25[degrees Celsius] showed better performance than the 16[degrees Celsius] group. We also found an interaction between anxiety and exploration traits on how individuals were affected by stressors during spatial learning. In summary, our findings confirm, for the first time, the existence of an inverted-U-shape memory function according to stressor intensity during the early learning and memory phases in a hippocampus-dependent task, and indicate the existence of individual differences related to personality-like profiles for performance at either high or low stress conditions. (As Provided).
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Erfasst von	ERIC (Education Resources Information Center), Washington, DC
Update	2017/4/10