Effect of one week of stress on emotional reactivity and learning and memory performances in Japanese quail.
Behavioural Brain Research. 2011-02-01; 217(1): 104-110
DOI: 10.1016/j.bbr.2010.10.004
Read on PubMed
Chronic stress is known to induce long term alterations of emotional behaviours
as well as cognitive performances leading thereby to welfare or husbandry
problems. These stress-induced consequences are observed following long periods
of stress lasting from several weeks to several years. The current study examined
whether a shorter period of stress (one week) produced similar impairing effects.
Two-week old Japanese quail were either submitted to a series of aversive events
over consecutive 8 days, at unpredictable times each day (treated animals) or
left undisturbed (controls). Following the treatment period, animals were weighed
and basal as well as aversive events-induced levels of plasma corticosterone were
quantified. Quail were also tested for emotional reactivity in three tests (the
tonic immobility test, the hole-in-the-wall and novel object tests) and for
spatial reference memory. Although there was no difference in corticosterone
levels between the two groups, the treated animals had lower body weight than
controls. Behavioural investigations after the treatment period did not reveal
any difference between the groups in the three emotional reactivity tests. In the
spatial task, treated quail displayed enhanced behavioural flexibility as
revealed by their higher performances during the reversal phase of the task. The
alteration of growth suggests that a short period of repetitive exposures to
unpredictable aversive events can be perceived by quail as stressful. Such a
stress period can improve spatial learning performances in quail supporting the
critical role played by the duration of the stress period on cognitive
performance.