Fig. 1.

LAT1 mRNA is expressed in brain microvascular cells and neurons. A To confirm that LAT1 mRNA is expressed in multiple cell types, radioactive LAT1 in situ hybridization (A1 darkfield image, silver grain accumulation represents LAT1 mRNA expression) was combined with dual immunofluorescence (A2) for vimentin (red) and HuC/D (green) to visualize the pericyte coverage of vessels and neuronal cell bodies, respectively. The area shown is from the rostral part of the rat hypothalamic supraoptic nucleus (SO). In the merge image (A3), note that silver grains form dense clusters over blood vessels (arrows), while a lesser degree of silver grain accumulation is present over neuronal cell bodies (yellow arrowheads). oc optic chiasm, SO supraoptic nucleus. B, C LAT1 in situ hybridization was co-localized with LAT1 immunofluorescence (red) that labels the vascular endothelium. Note that silver grain clusters that represent high LAT1 mRNA expression are formed over capillaries denoted by LAT1 immunofluorescence (arrows in B3, C3). Images are from the rat hypothalamic ventromedial nucleus (B) and the mouse hypothalamic arcuate nucleus (C). Scale bar 50 µm for all images