Neurotoxicity of the Cyanotoxin BMAA Through Axonal Degeneration and Intercellular Spreading

Neurotox Res. 2018 Jan;33(1):62-75. doi: 10.1007/s12640-017-9790-1. Epub 2017 Aug 25.


β-Methylamino-L-alanine (BMAA) is implicated in neurodegeneration and neurotoxicity, particularly in ALS-Parkinson Dementia Complex. Neurotoxic properties of BMAA have been partly elucidated, while its transcellular spreading capacity has not been examined. Using reconstructed neuronal networks in microfluidic chips, separating neuronal cells into two subcompartments-(1) the proximal, containing first-order neuronal soma and dendrites, and (2) a distal compartment, containing either only axons originating from first-order neurons or second-order striatal neurons-creates a cortico-striatal network. Using this system, we investigated the toxicity and spreading of BMAA in murine primary neurons. We used a newly developed antibody to detect BMAA in cells. After treatment with 10 μM BMAA, the cyanotoxin was incorporated in first-degree neurons. We also observed a rapid trans-neuronal spread of BMAA to unexposed second-degree neurons in 48 h, followed by axonal degeneration, with limited somatic death. This in vitro study demonstrates BMAA axonal toxicity at sublethal concentrations and, for the first time, the transcellular spreading abilities of BMAA. This neuronal dying forward spread that could possibly be associated with progression of some neurodegenerative diseases especially amyotrophic lateral sclerosis.

Keywords: Axonal degeneration; BMAA; Microfluidics; Neurotoxic; Spread.

MeSH terms

  • Amino Acids, Diamino / toxicity*
  • Analysis of Variance
  • Animals
  • Axons / drug effects*
  • Axons / pathology
  • Brain / cytology
  • Cells, Cultured
  • Cyanobacteria Toxins
  • Dose-Response Relationship, Drug
  • Embryo, Mammalian
  • Glial Fibrillary Acidic Protein / metabolism
  • Lab-On-A-Chip Devices
  • Mice
  • Microtubule-Associated Proteins / metabolism
  • Nerve Degeneration / chemically induced*
  • Nerve Degeneration / pathology*
  • Nerve Net / drug effects
  • Nerve Net / metabolism
  • Neurons / cytology
  • Neurons / drug effects*
  • Neurotoxins / toxicity*
  • Transcytosis / drug effects
  • Tubulin / metabolism


  • Amino Acids, Diamino
  • Cyanobacteria Toxins
  • Glial Fibrillary Acidic Protein
  • Microtubule-Associated Proteins
  • Mtap2 protein, mouse
  • Neurotoxins
  • Tubulin
  • beta3 tubulin, mouse
  • beta-N-methylamino-L-alanine