The cyanobacterial toxin β-N-methylamino- L -ala-
nine (BMAA) now appears to be a cause of Guamanian amyo-
trophic lateral sclerosis/parkinsonism dementia complex
(ALS/PDC). Its production by cyanobacteria throughout the
world combined with multiple mechanisms of BMAA neuro-
toxicity, particularly to vulnerable subpopulations of motor
neurons, has significantly increased interest in investigating
exposure to this non-protein amino acid as a possible risk
factor for other forms of neurodegenerative illness. We here
provide a brief overview of BMAA studies and provide an
introduction to this collection of scientific manuscripts in this
special issue on BMAA.

• BMAA and Neurodegenerative Illness