Figure 3: ENTs and adenosine receptors distribution in the human brain In the human fetal brain a distribution of human equilibrative nucleoside transporters 1 (hENT1) is found to be predominant compared with hENT2 (hENT1 > hENT2) in the cortex and the hippocampus, compared with a higher abundance of hENT2 (hENT2 > hENT1) in the thalamus, medulla oblongata, spinal cord and cerebellum. In addition, a higher abundance of A1 adenosine receptors (A1AR) compared with A2AAR (A1AR > A2AAR) is detectable in the cortex, hyppocampus, medulla oblongata, spinal cord and cerebellum. However, A2AAR is abundant in the thalamus compared with A1AR (A2AAR > A1AR). From data in references [17,70,71].