Odontoblast: a mechano-sensory cell

Odontoblasts are organized as a single layer of specialized cells responsible for dentine formation and presumably for playing a role in tooth pain transmission. Each cell has an extension running into a dentinal tubule and bathing in the dentinal fluid. A dense network of sensory unmyelinated nerve fibers surrounds the cell bodies and processes. Thus, dentinal tubules subjected to external stimuli causing dentinal fluid movements and odontoblasts/nerve complex response may represent a unique mechano-sensory system giving to dentine-forming cells a pivotal role in signal transduction. Mediators of mechano-transduction identified in odontoblast include mechano-sensitive ion channels (high conductance calcium-activated potassium channel--K(Ca)--and a 2P domain potassium channel--TREK-1) and primary cilium. In many tissues, the latter is essential for microenvironment sensing but its role in the control of odontoblast behavior remains to be elucidated. Recent evidence for excitable properties and the concentration of key channels to the terminal web suggest that odontoblasts may operate as sensor cells.