Is a selective stimulation of the rat incisor tooth pulp possible?

• Published in: Pain (Amsterdam) Vol. 15; no. 1; pp. 27 - 34
• Main Authors: Engstrand, P., Shyu, B.-C., Andersson, S.A.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 1983
• ISSN: 0304-3959; 1872-6623
• DOI: 10.1016/0304-3959(83)90004-0

The purpose of the present study was to investigate whether electrical stimulation via bipolar intradental or extrapulpal electrodes can selectively activate intrapulpal nerve fibres of the rat lower incisor. The compound action potential was recorded from the mandibular nerve following stimulation. This potential had the same threshold and latency before and after apical pulp extirpation. Transection of the inferior alveolar nerve distal to the connexion between the tooth pulp afferents and this nerve abolished the response. It was also possible to record action potentials of the same shape and amplitude both from the mandibular and the inferior alveolar nerve following the same intrapulpal stimulus. It is concluded that the major part of the compound action potential obtained by stimulating the rat incisor tooth pulp is not produced by pulp afferents but by activity in nerve fibres outside the pulp. The results suggest that electrical stimulation of the rat incisor tooth is not a useful method for physiological studies of nociceptive mechanisms.