Fig. 2
Carbon isotope labelling in the brain following 48 h pulse with 13C-labeled glucose: comparison of the striatum and substantia nigra pars compacta. a Representative light microscopy image of the striatal tissue showing a toluidine blue-stained semi-thin section (upper panel), adjacent to a map of 13C isotope enrichment in the same brain region (lower panel). Note the weak 13C labeling mainly present in neuronal cell bodies (*). b Representative light microscopy image of the substantia nigra pars compacta showing large neuronal cell bodies and neurites with intense 13C enrichment (arrowheads). To facilitate direct comparison, the same color-coded δ13C (‰) intensity scale is applied in (a) and (b). Scale bars: 20 µm