Taeko Hata*, Hiroyuki Nishikawa, Eiji Itoh and Yoshinori Funakami
Department of Pharmacology, Faculty of Pharmaceutical Sciences, Kinki
University, 3-4-1 Kowakae, Higashi-Osaka 577-8502, Japan
*Corresponding author. FAX: +81-6-6721-2353
E-mail: hata_t@phar.kindai.ac.jp
Abstract: To clarify the relationship between SART (specific alternation
of rhythm in temperature) stress (repeated cold stress) and anxiety, the
effects of various types of stress on the behavior of mice were studied
in elevated plus-maze tests and then the effects of anxiolytics were evaluated.
The percentage of time spent in the open arms of the plus-maze apparatus
decreased in mice subjected to SART stress without change in the total number
of arm entries. No change was noted in mice subjected to other stresses,
such as 1-h, 2-day and 5-day cold stress and 1-h, 15-h and 5×15-h restraint
stress. The reduction in the percentage of time spent in the open arms caused
by SART stress was inhibited by single and repeated administrations of diazepam
and alprazolam and by a single administration of buspirone, which have no
influence on the percentage of time spent in the open arms in nonstressed
mice, but not by flumazenil, WAY-100635 and chronic treatment with buspirone.
The effects of diazepam and buspirone were antagonized by flumazenil and
WAY-100635, respectively. The behavior of SART-stressed mice in the plus-maze
would thus appear to arise from anxiety, to which benzodiazepine and serotonin
receptors are related, but the diazepam binding inhibitor, an endogenous
anxiogenic protein, is not. Thus SART-stressed animals may be useful for
investigating the psychopharmacological and neuropharmacological basis of
anxiety.
Keywords: Elevated plus-maze, Stress, SART stress, Anxiety, Repeated
cold stress
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