K channels and action potential in dorsal root ganglion of diverse animals

The phenotype of action potentials (AP) in mammalian dorsal root ganglion (DRG) neurons is biphasic and thereby distinct from those in the CNS and spinal cord. The sensation of pain by DRG and its prevention may occur via many types of channels, receptors, and neurotransmitters; these are at least Cav, Kv, Nav, and TRP. The Cav, Kv, and Nav channels are prevailingly involved in the excitability of DRG neurons, while the TRP family enables the mechanosensitivity. The latter are the main family of channels, and thereby the list is extensive because of the presence of many distinct α subunits among them. Also, all major receptor channels are described in DRG, but purinergic ones could be considered important because of sensitization to ATP as a neurotransmitter. This work presents a comparative and detailed synthesis of the electrophysiological properties of intact DRG and isolated neurons, with an emphasis on the K channels involved in action potential generation.