Sulfatide with different fatty acids has unique distributions in cerebellum as imaged by Time-Of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS)

In order to elucidate the biological role of sulfatide it is important to define the cellular and subcellular distribution of its various molecular species (e.g. fatty acid chain length and hydroxylation). We determined sulfatide species distribution in the rat cerebellum using time-of-flight secondary ion mass spectrometry (TOF-SIMS). TOF-SIMS detects ions up to m/z 10000 and enables simultaneous imaging of the lateral distribution of substances on an exposed surface, in this case a section through cerebellum. In addition to TOF-SIMS we analyzed sulfatide distribution in rat cerebellum using a sulfatide monoclonal antibody and confocal laser scanning microscopy. In the white matter, TOF-SIMS showed a uniform distribution of sulfatide with short chain fatty acids and a patchy distribution of sulfatide with C24 fatty acids. These patches had a low cholesterol signal. The granular layer showed a more uniform distribution of the sulfatide species, with the highest signal of C24. The molecular layer and Purkinje cells were devoid of sulfatide signals. Immunofluorescence showed the highest intensity in the white matter, lower intensity in the granular layer and absence of fluorescence in the molecular layer and Purkinje cells. The results are discussed in relation to previously published data and possible functional roles.