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Background and Objective: After chronic stress, brain volume and weight reduces and in turn, adrenal weight and volume increases. This study was performed to determine the effect of chronic stress and memantine administration within amygdala on the alterations of brain’s volume and weight ratio to volume and weight of the adrenal gland on male mice.

Methods: In this experimental study, bi- or unilateral amygdala cannulation was preformed stereotaxically. A week after recovery, animals were received different doses of memantine (1, 0.5, and 0.1 µg/mouse), five min before stress induction. Electric foot shock induced to animals for seven consecutive days. At the end of the seventh day, animals were sacrificed and their brain and adrenal glands were fixed in formalin 4%. The volume and weight was determined by mercury immersion and accurate balance respectively.

Results: Stress non- significantly reduced brain’s volume ratio to volume of the adrenal gland and brain’s weight ratio to weight of the adrenal gland. Memantine administration within amygdala inhibited stress effect. Memantine administration in low and medium doses within right and left amygdala significantly increased brain’s volume and weight ratio to volume and weight of the adrenal gland (P<0.05).

Conclusion: Memantine dose and side dependently inhibits the effect of induced stress in male mice. Also, unilateral memantine administration within the left and right amygdala was more effective.

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Background and Objective: Memantine (MEM) an uncompetitive N-methyl-D-aspartate receptor antagonist is used for treatment of patients with Alzheimer disease. This study aimed to examine the effect of Memantine on the spatial learning and memory in electrical lesion’s model of nucleus basalis magnocellularis (NBM) in animal model of Alzheimer's disease.
Methods: In this experimental study, 56 adult male Wistar rats were allocated into eight groups: control group; lesion group, which received bilateral electrically lesion (0.5 mA, 3s) in NBM; sham group (the electrode was entered into the NBM with no lesion); Memantine groups (lesion+1 mg/kg/bw of MEM; lesion+3 mg/kg/bw of  MEM; lesion+5 mg/kg/bw of  MEM; lesion+7 mg/kg/bw of MEM) and Vehicle group (lesion+0.2 mL saline). After one week, animals were trained to perform the Y-maze task for five days. Twenty five days after training, a retention test was performed to determine long-term memory.
Results: The bilateral lesion of NBM impaired the spatial learning compared to the control and sham groups (P<0.05). No effect on spatial learning was seen in saline group compared with the lesion group. The treatment with Memantine in  lesion+MEM 3 mg/kg/bw, lesion+MEM 5mg/kg/bw and lesion+MEM 7mg/kg/bw groups significantly improved spatial learning (P<0.05). Moreover, no significant difference of memory was observed between the results in the 5th day of training and the retention test of the 30th day.
Conclusion: Treatment with memantine improves spatial learning defects in electrical leisions model of NBM of Alzheimer's disease in dose dependent manner in animal model.