Ependyma as a Possible Morphological Basis of Ischemic Preconditioning Tolerance in Rat Spinal Cord Ischemia Model: Nestin and Fluoro-Jade B Observations

This study investigates how a brief, non-lethal period of reduced blood flow (ischemic preconditioning or IPC) can protect the spinal cord from a subsequent, more severe ischemic injury. The researchers used markers for cell proliferation (nestin) and cell degeneration (Fluoro-Jade B) to examine the effects of IPC in rats. The spinal cord ependyma plays a significant role in neuronal regeneration in lower vertebrates. This study looked at the immunohistochemical response of ependyma in rats, to see if ependymal cells may contribute to ischemic resistance in IPC. The study compared rats that experienced a 12-minute ischemic event with rats that were preconditioned with a 3-minute ischemic event followed by a period of restored blood flow before the 12-minute ischemic event. The researchers then analyzed the spinal cord tissue at different time points after the ischemic events to assess cell damage and regeneration.

• 1
  Twelve-minute ischemia induced nestin positivity in ependyma and reactive astrocytes at the L1−3 spinal cord segments. This identifies the L1-L3 region as viable after the ischemic event.
• 2
  Fluoro-Jade B-positive cells were abundant throughout the dorsal horn and intermediate zone of L4–S2 segments in rats that underwent ischemia. This indicates that the L4-S2 segments were the most injured spinal cord region.
• 3
  Rats that underwent IPC treatment had fewer nestin-positive ependymal cells and reactive astrocytes in the lower lumbar and sacral spinal cord segments. The appearance of nestin-positive cells in the segments that should have been affected by ischemia indicates protection of this region by the IPC treatment.