Free-choice alcohol drinking reduces sphingomyelin levels in the dorsal hippocampus (DH) of mice over-expressing acid sphingomyelinase (tgASM). The MALDI images were acquired with x–y-raster widths of 30 µm for coronal sections. Slice MALDI mass spectrograms for the three most abundant sphingomyelin (SM) species in the neuropil of the DH of water or 16 vol% alcohol (EtOH) drinking tgASM or wild type (WT) mice with regular consumption and three withdrawal and reinstatement episodes. The DH was analyzed as a target area of interest. The errorbars show the mean of eight samples/genotype–treatment (±SEM) for four animals. The data are shown using a rainbow scale that is normalized against the total ion count. a The coronal tissue sections show that SM 18:1 18:0 is enriched in the hypothalamus, amygdala, and DH. b The abundance of SM 18:1 18:0 was not changed in tgASM mice (p > 0.05). Alcohol drinking reduces levels of SM 18:1 18:0 in WT and tgASM mice to the same degree (ANOVA, factor treatment: F
1,28 = 63.281, p < 0.001). c The coronal tissue sections show that SM 18:1 18:1 is particularly enriched in the amygdala and hypothalamus. d The abundance of SM 18:1 18:1 was not changed in tgASM mice (p > 0.05). Alcohol drinking reduces levels of SM 18:1 18:1 in WT and tgASM mice to the same degree (ANOVA, factor treatment: F
1,28 = 80.920, p < 0.001). e The coronal tissue sections show SM 18:1 20:0 enriched in the thalamus and ventricles. f The abundance of SM 18:1 20:0 was not changed in tgASM mice (p > 0.05). Alcohol drinking reduces levels of SM 18:1 20:0 in WT and tgASM mice to the same degree (ANOVA, factor treatment: F
1,28 = 36.964, p < 0.001). g Mass spectrogram for a single slice point at the DH level with SM target masses. h Anatomical analysis of the slice at level of the Nac (Amyg amygdala, cc corpus callosum, ci commisura interior, Ctx cortex, dHipp dorsal hippocampus, Hyp hypothalamus, Thal thalamus). For an overview on white matter and liquor associated SM species, see Suppl. Figure 8, 9 (***p < 0.001)