NEURAL FORM OF VOLTAGE-DEPENDENT SODIUM CURRENT IN HUMAN CULTURED DENTAL-PULP CELLS

Intradental, i.e. pulpal, cells may play an important part in sensory transduction in teeth, although the cellular mechanisms and the identi ty of the specific cell types involved are still unclear. Because the majority of cells in dental pulp are derived from neural crest, it see med likely that these might have the membrane properties of other neur al-derived cells found in the peripheral or central nervous system. Th e patch-clamp recording technique was used to show that cells in expla nt cultures from human dental pulp contain a voltage-gated, tetrodotox in-sensitive inward current. Mean activation potential of the current was -42 +/- 2.5 mV and the voltage at half-inactivation was -79.4 +/- 5.3 mV, suggesting a neural-like sodium conductance. In addition, thes e cells were immunoreactive to glial acidic fibrillary protein, growth -associated protein (GAP-43), and vimentin, further suggesting that de ntal pulp contains a population of cells with membrane properties simi lar to neuronal satellite cells. These cells may contribute, either di rectly or indirectly, to somatosensation in teeth.