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Modulating the effects of chronic stress through increasing the activity of the adrenergic system
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Masoumeh Sarfi   , Mahmoud Elahdadi Salmani *  , Taghi Lashkarbolouki , Iran Goudarzi |
| School of biology, Damghan University, Damghan, Iran |
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Abstract: (470 Views) |
Background and aims: Noradrenergic system is involved in stress and anxiety related behaviors. The neural pathways of stress and the noradrenergic system in the hippocampus have a reciprocal effect on each other. Therefore, in this study, the effect of noradrenergic activity on anxiety and learning under stress conditions is investigated.
Methods: Adult male Wistar rats weighing 180-230 were given acute (3 days) or chronic (21 days) restrained stress. Yohimbine was injected with a dose of 2 mg/kg (intraperitoneally) to activate the noradrenergic system. After 24 hours from the last stress session, social learning and then anxiety and exploratory behavior and new object recognition were investigated in animals.
Results: The amount of association with a familiar rat (stranger 1) decreased due to acute (p < 0.01) and chronic
(p < 0.001) stress and increased with a stranger rat (stranger 2). The time in the open arm of the elevated plus maze decreased (p < 0.001) due to acute and chronic stress, and animals receiving yohimbine, while the time increased
(p < 0.001) in the closed arm. The duration of immobility in the open field test increased due to acute (p < 0.01) and chronic (p < 0.001) stresses, while it decreased after yohimbine administration in the chronic (p < 0.001) stress group. The time spent with the familiar object was increased (p < 0.001) by chronic stress and decreased (p < 0.001) by acute stress and yohimbine administration.
Conclusion: This study showed that increasing the activity of the noradrenergic system moderates the effects of chronic stress, which indicates the possible cooperation of the glucocorticoid and adrenergic systems.
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| Keywords: Stress, Anxiety, Noradrenergic system, Learning and memory |
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Full-Text [PDF 1007 kb]
(670 Downloads)
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Type of Study: Original Research |
Subject:
Neuroscience
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