PMC9860447_01
BMAA and two BMAA isomers. All compounds have a molecular formula of C4H10N2O2 and molecular weight of 118.13 g/mol. (A) beta-N-methylamino-L-alanine or BMAA; IUPAC Name: (2 S)-2-amino-3-(methylamino)propanoic acid; PubChem CID:105089 (B) 2,4 diaminobutyric acid or 2,4-DAB; IUPAC Name: 2,4-diaminobutanoic acid; PubChem CID:470. (C) N-(2-aminoethyl)-glycine or AEG; IUPAC Name: 2-(2-aminoethylamino)acetic acid; PubChem CID:428913. Compounds were drawn using ChemDraw RRID:SCR_016768.
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Six postmortem subjects (47-78 years old) were evaluated for exposure to BMAA toxin and two of its structural isomers: N-(2-aminoethyl)-glycine (AEG) & 2,4-diaminobutyric acid (2,4-DAB), which has also been shown to be neurotoxic in humans (Fig. 1; Table 1).
Olfactory bulb and tract dissection. (A) Gross examination of the ventral aspect of the cerebrum, brainstem, and cerebellum from a male with Alzheimer's disease (age 91 years) to highlight the collection and dissection of the olfactory bulb (Ob) and tract (Ot). Fc= frontal cortex; Tc= temporal cortex; Pc= parietal cortex; Crb= cerebellum. (B) Higher magnification of the region of interest (black dotted box) shown in panel A. 1:Ob used for UHPLC-MS/MS; 2:Ob utilized in qPCR experiments and 3:Ot sampled for histopathology analysis. Photograph taken by the University of Miami Brain Endowment Bank.
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Ob and olfactory tracts (Ot) were photographed, dissected, and frozen in 2-methylbutane at -42 C for use in toxicological and gene expression assays. Or, fixed in 10 % neutral buffered formalin for histopathological examination (Fig. 2).