Single ion images of
the BMAA-induced hippocampal changes. Manual
inspection of variables (m/z) that
showed the highest loading values in MAF based image analysis. (Camera
image shows histopathological lesions observed in the CA1 region.)
(A) In positive mode, the MAF data show phosphatidylcholine headgroup
(PC, m/z 184) and its fragments
(m/z 86 (TME, C5H12N+), m/z 104
(choline, C5H14NO+)) to be increased
and localized to the CA1 in BMAA-treated rats, suggesting elevated
phospholipid levels as a consequence of gliosis. Similarly, specific
amino acid fragments (m/z 30, glycine; m/z 72, valine; m/z 88, aspartate) were increased at the BMAA-induced lesions
in CA1 indicating protein increase, as a result of gliosis or protein
aggregation. In addition, increased potassium (K+) levels
were observed that localize to the lesions. (B) Similar findings were
observed for protein fragments (CN–, C2HO–, CNO–) in negative mode.
Furthermore, elevated cholesterol levels were observed in the MAF
loadings, which is a consequence of the adjacent white matter region
(m/z 385). (Image size 250 ×
250 μm; color scale indicates relative intensity in %.)