Many cyanobacteria make a neurotoxin

A brain-damaging toxin, once believed to come only from a group of tropical plants and their live-in microbes, turns out to be much more widespread.

The discovery comes out of investigations into a long-standing medical mystery. During the last century, a neurological disease akin to amyotrophic lateral sclerosis spiked among the Chamorro people in Guam. An international research team led by Paul Cox of the National Tropical Botanical Garden based in Kalaheo, Hawaii, has suggested that the spike came from a rise in exposure to the neurotoxic amino acid β-N-methylamino-L alanine (BMAA).