Facilitative UT-B urea transporters in the brain play an important role in regulating levels of urea in various cell types, including astrocytes. Numerous studies have reported increased UT-B RNA expression with ageing and in a variety of neurological disorders, such as Alzheimer’s Disease, particularly in the hippocampal regions. However, much less in known about the effects of these conditions on UT-B transporter protein abundance and function. This current study therefore compared the levels of both UT-B RNA and UT-B protein in young (3-5 months old) and aged (18-24 months old) male C57BL/6 mice. Animals were euthanized to provide tissue for undergraduate teaching activities. Postmortem brain tissue was subsequently isolated for research purposes in accordance with a tissue-sharing initiative, following approval of the UCD Animals Ethics Committee. All data shown as mean ± S.E.M. As expected, endpoint RT-PCR experiments initially showed that the UT-B/GAPDH RNA expression ratio increased in aged mouse hippocampus (0.27 ± 0.12 vs 0.95 ± 0.09, P=0.0131, N=3, unpaired T-Test). Importantly, this change was confirmed at the protein abundance level, as western blotting experiments revealed that the 30-35 kDa UT-B1 signal/protein ratio was also significantly increased in aged mouse hippocampus (0.76 ± 0.21 vs 1.83 ± 0.43, P=0.0426, N=5-6, unpaired T-Test). Further investigations showed similar increases in UT-B1 protein abundance in the cerebellum, frontal cortex and occipital cortex regions (all P<0.05, N=3, unpaired T-Test). In contrast, no such changes occurred in the abundance of MCT1 short chain fatty acid transporters (all NS, N=3, unpaired T-Test). These data therefore confirmed that specific increases in UT-B1 protein abundance occur throughout the regions of the aged mouse brain. Further studies are now needed to investigate both the precise cellular location and functional consequence of these increased UT-B1 protein levels.