EVIDENCE FOR PRIMARY AFFERENT DEPOLARIZATION OF SINGLE TOOTH-PULP AFFERENTS IN THE CAT

  • 1 January 1979
    • journal article
    • research article
    • Vol. 288  (MAR) , 437-447
Abstract
Responses of single tooth-pulp afferents to electrical stimulation of sites in the trigeminal sensory nuclear complex were recorded from canine teeth in cats. Changes in the excitability of the central terminals of a pulpal afferent after stimulation of other groups of sensory nerves were used as evidence for changes in their polarization. Electrical stimulation of nerves in other teeth resulted in raised excitability of the central terminals of pulp afferents lasting up to 300 ms. The greatest effects were observed after the ipsilateral infraorbital nerve was stimulated. This occurred when only nerve fibers with conduction velocities in the A.alpha. range were excited. Mechanical stimulation of a canine tooth produced increases in terminal excitability of pulpal afferents innervating the same tooth. A similar effect was observed after a brief pull on a group of ipsilateral mystacial vibrissae. No evidence of decreases in the excitability of the central terminals of toothpulp afferents was obtained with the conditioning stimuli.