Author/Authors :
Nikbakht Farnaz نويسنده , Malekpour Farzaneh نويسنده Department of Clinical Psychology School of Education & Psychology University of Shiraz, Eram Campus, Shiraz, Iran , Homayouni Amir Sina نويسنده Department of Physiology and Physiology Research Center - Iran University of Medical Sciences , Belali Rafie نويسنده Department of Physiology and Physiology Research Center - Iran University of Medical Sciences , Shahbazi Ali نويسنده Neuroscience Department - Iran University of Medical Sciences
Abstract :
Background and Objective: It is well known that stress and glucocorticoid, modulate memory processing, though the result is completely dependent on the time of stress induction. This study investigated the effect of acute corticosterone administration on memory retrieval of recent and remote memory in a 4 trials/day (low- intensity learning) or 8 trials/ day (high- intensity learning) Morris water maze protocol.
Materials and Methods: Sixty four adult male Wistar rats were used in this research study. Corticosterone was injected subcutaneously (3 mg/kg) 30 min before the probe trial test of Morris water maze. Control animals received the vehicle.
Results: Acute corticosterone, thirty minutes before probe test led to impairment of memory retrieval phase in recent (p < 0.01) and remote memory (p < 0.001). A high intensity learning protocol (eight trials/ day) was then used to show if an enhancement of learning could prevent corticosterone-induced memory impairment.
Conclusion: Apparently, learning enhancement was just effective for protecting deleterious effects of corticosterone in recent memory and had no effect on remote memory. Thus, acute stress may impair memory retrieval in a time-dependent manner.
