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

Tsong Hai Lee, Jen Tsung Yang, Jr Rung Lin, Chaur Jong Hu, Wen Hai Chou, Ching Po Lin, Nai Fang Chi

Research output: Contribution to journalArticlepeer-review

Abstract

Ischemic preconditioning with non-lethal ischemia can be protective against lethal forebrain ischemia. We hypothesized that aging may aggravate ischemic susceptibility and reduce brain plasticity against preconditioning. Magnetic resonance diffusion tensor imaging (DTI) is a sensitive tool to detect brain integrity and white matter architecture. This study used DTI and histopathology to investigate the effect of aging on ischemic preconditioning. In this study, adult and middle-aged male Mongolian gerbils were subjected to non-lethal 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 anisotropy (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 in 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 than 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. This study thus suggests an age-dependent protective effect of ischemic preconditioning against both neuronal apoptosis and dendritic injury in hippocampus after forebrain ischemia. (Figure presented.).

Original languageEnglish
Pages (from-to)430-447
Number of pages18
JournalJournal of Neurochemistry
Volume155
Issue number4
DOIs
Publication statusPublished - Nov 2020

Keywords

  • aging
  • diffusion tensor imaging
  • immunohistochemistry
  • ischemic preconditioning

ASJC Scopus subject areas

  • Biochemistry
  • Cellular and Molecular Neuroscience

Fingerprint Dive into the research topics of 'Protective effects of ischemic preconditioning against neuronal apoptosis and dendritic injury in the hippocampus are age-dependent'. Together they form a unique fingerprint.

Cite this