Cyanobacterial Neurotoxin Beta-Methyl-Amino-l-Alanine Affects Dopaminergic Neurons in Optic Ganglia and Brain of Daphnia magna

• Published in: Toxins Vol. 10; no. 12; p. 527
• Main Authors: Brooke-Jones, Megan, Gáliková, Martina, Dircksen, Heinrich
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 08.12.2018; MDPI
• Subjects: Alanine; Amino acids; Amino Acids, Diamino - toxicity; Amyotrophic lateral sclerosis; Animals; Bacterial Toxins - toxicity; Basal ganglia; beta-methyl-amino- l -alanine; Bioaccumulation; Biological magnification; Biosynthesis; BMAA; Brain; Brain - cytology; Brain - drug effects; Central nervous system diseases; Cyanobacteria; cyanobacterial toxin; Cytometry; Daphnia; Daphnia magna; Dementia; Dementia disorders; Dopamine; Dopamine receptors; dopaminergic neurons; Dopaminergic Neurons - drug effects; Ecosystems; Environmental Sciences; Enzymes; Female; Females; Fertility; Fluorescence; Food chains; Food webs; Ganglia; Ganglia - drug effects; Hydroxylase; Immunohistochemistry; L-Alanine; miljövetenskap; Movement disorders; Nervous system; Neurodegeneration; Neurodegenerative diseases; Neurological disorders; Neurons; Neurotoxins; Neurotoxins - toxicity; Offspring; Organisms; Plankton; Reproduction - drug effects; Swimming; Toxins; Tyrosine; water flea; zoologi; Zoology; Zooplankton; Guam; United States > US; Sweden; water flea; BMAA; cyanobacterial toxin; dopaminergic neurons; neurodegeneration; beta-methyl-amino-l-alanine; Daphnia magna
• ISSN: 2072-6651; 2072-6651
• DOI: 10.3390/toxins10120527

The non-proteinogenic amino acid beta-methyl-amino-l-alanine (BMAA) is a neurotoxin produced by cyanobacteria. BMAA accumulation in the brain of animals via biomagnification along the food web can contribute to the development of neurodegenerative diseases such as Amyotrophic lateral sclerosis/Parkinsonism dementia complex (ALS/PDC), the latter being associated with a loss of dopaminergic neurons. is an important microcrustacean zooplankton species that plays a key role in aquatic food webs, and BMAA-producing cyanobacteria often form part of their diet. Here, we tested the effects of BMAA on putative neurodegeneration of newly identified specific dopaminergic neurons in the optic ganglia/brain complex of using quantitative tyrosine-hydroxylase immunohistochemistry and fluorescence cytometry. The dopaminergic system was analysed in fed and starved isogenic adults incubated under different BMAA concentrations over 4 days. Increased BMAA concentration showed significant decrease in the stainability of dopaminergic neurons of , with fed animals showing a more extreme loss. Furthermore, higher BMAA concentrations tended to increase offspring mortality during incubation. These results are indicative of ingested BMAA causing neurodegeneration of dopaminergic neurons in and adversely affecting reproduction. This may imply similar effects of BMAA on known human neurodegenerative diseases involving dopaminergic neurons.