Targeting N-methyl-D-aspartate 2B receptor in painful diabetic neuropathy – mechanisms, challenges, and emerging therapeutics

Figure 1 Schematic representation of an N-methyl-D-aspartate receptor-2B structure and its pharmacological regulation sites. An N-methyl-D-aspartate receptor-2B consists of four subunits with three transmembrane domains (M1, M3, and M4) and a pore (M2) that allows ion influx. The receptor is also characterised by an extracellular amino-terminal, an extracellular ligand-binding, four transmembrane, and an intracellular C-terminal domains. ATD: Amino-terminal domain; Ca²⁺: Calcium ion; CTD: C-terminal domain; LBD: Ligand-binding domain; Mg²⁺: Magnesium ion; TMD: Transmembrane domain. Adapted from Gallo et al[14] (Supplementary material).