The Role of Amnesia Caused by Cerebral Hypoperfusion on Depression-Like Behavior in Male Wistar Rats

Anxiety disorders, depression, and dementia are common in elderly, which may overlap in various neurological disorders. Stress can be a risk factor for long-term depression. It also suggests that depression plays a role in developing dementia. Amnesia is the most problem in dementia. Is amnesia a risk factor for depression? Considering the common underlying mechanisms for causing these disorders, the purpose of this study is to investigate the role of amnesia in developing depression.

Forty-eight wistar rats were divided into two main groups (sham-A and intervention-B) and four subgroups (Control-C, Chronic mild stress-D, hypoperfusion without stress-E, hypoperfusion with Mild stress-F). Permanent occlusion of bilateral common carotid artery was performed to induce cerebral hypoperfusion. Radial arm maze test and chronic unpredictable mild stress were used to evaluate amnesia and depression, respectively. Forced swim test was performed to assess severity of depression and finally we used neuronal count for evaluating cellular degeneration in the CA1 hippocampus region.

Cerebral hypoperfusion causes amnesia and significantly reduced the mean number of cells in the hippocampal CA1 area. Cerebral hypoperfusion and stress significantly increased the incidence of depression-like behavior.

Amnesia caused by cerebral hypoperfusion can increase the risk of depression, especially under stressful situations.