Postischemic PKC activation rescues retrograde and anterograde long-term memory

Proc Natl Acad Sci U S A. 2009 Aug 25;106(34):14676-80. doi: 10.1073/pnas.0907842106. Epub 2009 Aug 10.

Abstract

Therapeutics for cerebral ischemia/hypoxia, which often results in ischemic stroke in humans, are a global unmet medical need. Here, we report that bryostatin-1, a highly potent protein kinase C (PKC) activator, interrupts pathophysiological molecular cascades and apoptosis triggered by cerebral ischemia/hypoxia, enhances neurotrophic activity, and induces synaptogenesis in rats. This postischemic therapeutic approach is further shown to preserve learning and memory capacity even 4 months later as well as long-term memory induced before the ischemic event. Our results of electromicroscopic and immunohistochemical analyses of neuronal and synaptic ultra-structure are consistent with a PKC-mediated synaptic remodeling and repair process that confers long-lasting preservation of spatial learning and memory before and after the cerebral ischemic/hypoxic event, suggesting a previously undescribed therapeutic modality for cerebral ischemia/hypoxia and ischemic stroke.

MeSH terms

  • Animals
  • Apoptosis / drug effects
  • Brain Ischemia / physiopathology
  • Brain Ischemia / prevention & control*
  • Bryostatins / pharmacology
  • Dendritic Spines / drug effects
  • Dendritic Spines / ultrastructure
  • Enzyme Activation / drug effects
  • Enzyme Activators / pharmacology*
  • Hippocampus / cytology
  • Hippocampus / drug effects
  • Hippocampus / metabolism
  • Hypoxia / physiopathology
  • In Situ Nick-End Labeling
  • Male
  • Maze Learning / drug effects
  • Memory / drug effects*
  • Memory / physiology
  • Microscopy, Electron
  • Motor Activity / drug effects
  • Protein Kinase C / metabolism*
  • Rats
  • Rats, Wistar
  • Synaptic Vesicles / drug effects
  • Synaptic Vesicles / ultrastructure
  • Time Factors

Substances

  • Bryostatins
  • Enzyme Activators
  • Protein Kinase C