Semnan University of Medical Sciences

Research and Technology Vice Chancellor

Rashidy-Pour, Ali and Sadeghi, Hassan and Taherain, Abbas Ali and Vafaei, Abbas Ali and Fathollahi, Yaghoub (2004) The effects of acute restraint stress and dexamethasone on retrieval of long-term memory in rats: an interaction with opiate system. Behavioural brain research, 154 (1). pp. 193-8. ISSN 0166-4328

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    This study investigated whether application of acute restraint stress or dexamethasone, as a glucocorticoid receptor agonist, impaired retrieval of long-term memory and if pretreatment with opiate antagonist naloxone blocked their effects on memory retrieval. Young adult male rats were trained in one trial inhibitory avoidance task (1 mA, 1.5 s footshock). On retention test given 48 h after training, the latency to re-enter dark compartment of the apparatus was recorded. Thirty minutes before retention test, the rats were exposed to a 10 min of restraint stress in a Plexiglass tube or were injected with dexamethasone (1 mg/kg) with or without prior treatment of naloxone (1 or 2 mg/kg). The results showed that both acute restraint stress and dexamethasone impaired retention performance. Both doses of naloxone were effective in blocking the impairing effect of stress, but only higher dose of naloxone blocked dexamethasone-induced impairment. The applied stress increased circulating corticosterone levels as assessed immediately after the retention test, indicating that stress-induced impairment of memory retrieval is mediated, in part, by increased plasma levels of glucocorticoids. These findings further indicate that acute restraint stress and glucocorticoids impair retrieval of long-term memory, and provide evidence for the existence of an interaction between glucocortioids and opiate system on this process.

    Item Type: Article
    Subjects: R Medicine > R Medicine (General)
    Divisions: Faculty of Medical Sciences > School of Medicine
    Depositing User: Admin User
    Date Deposited: 17 Sep 2016 14:46
    Last Modified: 17 Sep 2016 14:46

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