Voltage-gated sodium channels, which produce the inward membrane current necessary for regenerative action potential production within the mammalian nervous system, are expressed in primary sensory neurons and have emerged as important targets in the study of the molecular pathophysiology of pain and in the search for new pain therapies[1]. Nine members of the family of voltage-gated sodium channels have been identified thus far, consisting of a large alpha subunit that associates with other proteins, such as beta subunits[2]. An alpha subunit, consisting on its own of four repeating trans-membrane domains forming the actual pore, forms the core of the channel and is functional on its own. When accessory proteins assemble with alpha subunits, the resulting complex can display altered voltage dependence and cellular localization. Ligand gated sodium channels (e.g. nicotinic receptors) are activated by endogenous acetylcholine. Activation causes a conformational change of the receptor, leading to the opening of the internal pore, and enabling extra-cellular sodium ions to flow into the cell.
As the quest for new selective molecules targeting sodium channels for the treatment of chronic pain continues, Axon Medchem intends to expand its range of sodium channel modulators accordingly.