Protective effects of ischemic preconditioning against neuronal apoptosis and dendritic injury in the hippocampus are age ‐dependent

In this study, adult and middle ‐aged male Mongolian gerbils were subjected to nonlethal 5‐min forebrain ischemia (ischemic preconditioning) or sham‐operation, followed by 3 days of reperfusion, and then lethal 15‐min forebrain ischemia. A 9.4‐Tesla MR imaging system was used to study DTI indices, namely fractional aniso tropy (FA), mean diffusivity (MD), and intervoxel coherence (IC) in the hippocampal CA1 and dentate gyrus (DG) areas. In situ expressions of microtubule‐associated protein 2 (MAP2, dendritic marker protein) and apoptosis were also examined. The 5‐min ischemia did not cause dendritic and neuronal injury and any significant change of DTI indices and MAP2 in adult and middle‐aged gerbils. The 15‐min ischemia induced significant delayed neuronal apoptosis and early dendritic injury evidenced by DTI and MAP2 studies in both CA1 and DG areas with more severe injury in middle‐aged gerbils t han adult gerbils. Ischemic preconditioning could improve neuronal apoptosis in CA1 area and dendritic integrity in both CA1 and DG areas with better improvement in adult gerbils than middle‐aged gerbils.Our present study thus suggests an age ‐dependent protective effect of ischemic preconditioning against both neuronal apoptosis and dendritic injury in hippocampus after forebrain ischemia.
Source: Journal of Neurochemistry - Category: Neuroscience Authors: Tags: ORIGINAL ARTICLE Source Type: research