Exposure to swainsonine impairs adult neurogenesis and spatial learning and memory

Toxicol Lett. 2015 Jan 5;232(1):263-70. doi: 10.1016/j.toxlet.2014.11.017. Epub 2014 Nov 18.

Abstract

Swainsonine (SW) is an indolizidine triol plant alkaloid isolated from the species Astragalus, colloquially termed locoweed. Ingestion induces severe neurological symptoms of livestock and wildlife, including ataxia, trembling, exaggerated fright reactions. Toxicity to the central and peripheral nervous system is caused by inhibition of lysosomal a-mannosidase (AMA) and accumulation of intracellular oligosaccharide. However, the effects of SW on adult neurogenesis and cognition have remained unclear. Therefore, the present study was conducted to examine the effects of SW on adult neurogenesis and learning as well as memory performance in adult mice. SW (10μg/mL in drinking water) was administered orally to mice for 4 weeks. Our results showed that SW reduced proliferation and survival of neural progenitor cells (NPCs) in culture, and in the hippocampus of adult mice. In addition, exposure to SW led to down-regulation of doublecortin (DCX) and synaptophysin (SYP) in the hippocampus. However, caspase 3 and glial fibrillary acidic protein (GFAP) levels were significantly increased in SW-treated mice. Finally, SW-treated mice exhibited deficits in hippocampus-dependent spatial learning and memory. Our findings suggest that SW affects adult neurogenesis and cognitive function.

Keywords: Adult neurogenesis; Learning and memory; Neural progenitor cells; Swainsonine.

MeSH terms

  • Animals
  • Behavior, Animal / drug effects*
  • Caspase 3 / metabolism
  • Cell Death / drug effects
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Cognition / drug effects
  • Doublecortin Domain Proteins
  • Doublecortin Protein
  • Glial Fibrillary Acidic Protein / metabolism
  • Hippocampus / drug effects*
  • Hippocampus / pathology
  • Hippocampus / physiopathology
  • Male
  • Maze Learning / drug effects
  • Memory / drug effects*
  • Mice, Inbred C57BL
  • Microtubule-Associated Proteins / metabolism
  • Neural Stem Cells / drug effects
  • Neural Stem Cells / pathology
  • Neurogenesis / drug effects*
  • Neuropeptides / metabolism
  • Signal Transduction / drug effects
  • Spatial Learning / drug effects*
  • Swainsonine / toxicity*
  • Synaptophysin / metabolism
  • Time Factors

Substances

  • Dcx protein, mouse
  • Doublecortin Domain Proteins
  • Doublecortin Protein
  • Glial Fibrillary Acidic Protein
  • Microtubule-Associated Proteins
  • Neuropeptides
  • Synaptophysin
  • Syp protein, mouse
  • Casp3 protein, mouse
  • Caspase 3
  • Swainsonine