The distribution and density of monocarboxylate transporter 2 in cerebral cortex, hippocampus and cerebellum of wild‐type mice

Monocarboxylates cannot cross the blood‐brain barrier freely to participate in brain energy metabolism. Specific monocarboxylate transporters ( MCT s) are needed to cross cellular membranes. Monocarboxylate transporter 2 ( MCT 2) is a major monocarboxylate transporter encoded by the SLC 16A7 gene. Recent studies reported that neurodegenerative diseases of the CNS , such as Alzheimer's disease ( AD ) and Parkinson's disease ( PD ), were related to energy metabolic impairment. MCT 2 also plays an important role in energy metabolism in the CNS . To provide experimental evidence for future research on the role of MCT 2 in the pathological process of CNS degenerative diseases, the distribution and density of MCT 2 in different subregions of wild‐type mouse brain was examined using immunohistochemistry, western blot and immunogold post‐embedding electron microscopic techniques. The amount of MCT 2 was higher in cerebellum than in cortex and hippocampus on western blots, and there was no statistical difference between cortex and hippocampus. Immunohistochemistry assay revealed the highest density of MCT 2 in the CA 3 of the hippocampus. The granular cell layer of the cerebellum contained more MCT 2 than the molecular layer. The MCT 2 density on the end feet of astrocytes of molecular layer was lower than in hippocampus, but the postsynaptic densities ( PSD s) of asymmetric synapses in the molecular layer exhibited a high density using immunogold post‐embedding electron microscopic techniques.