Figure 3.

Lactate uptake in cerebellar white matter and in whole-cell patch-clamped oligodendrocytes. A, Confocal image from the cerebellum showing white matter with granule cells on each side. B, Three successive pH responses to 10 mm lactate measured in the white matter. C, As in B, but with 100 μm phloretin present during the second response. D, The mean responses to lactate with and without phloretin in six slices with and four slices without phloretin. Error bars indicate SEM. E, Whole-cell patch-clamped oligodendrocyte in the cerebellar white matter filled with BCECF from the pipette. Left, Fluorescence image of the oligodendrocyte. The soma and the parts of the processes that were monitored are indicated (black and white rectangles, respectively). Middle, The fluorescence response to 10 mm lactate in the soma of the cell. Right, The fluorescence response to lactate in the indicated processes. In both areas, lactate evokes a clear acidification, superimposed on some baseline drift.