Assessment of the Outcomes of Cerebral Blood Flow Measurements After Electrical Stimulation of Upper Right Incisor Tooth in Rabbits

Abstract

The cerebral vessels are innervated by sympathetic, parasympathetic, and sensory nerves. A sensory innervation of the cerebral vessels originating in the trigeminal ganglion has been described in a number of species by several investigations. It has been shown that the electrical stimulation of the trigeminal ganglion causes an increase of cerebral cortical blood flow (CCoBF). The aim of the present study was to determine the effects of dental electrical stimulation the CCoBF in rabbits. A stimulating electrode was located in the upper right incisor tooth of rabbits and trigeminal ganglion was stimulated orthodromically via the infraorbital nerve. Variations in the cortical CCoBF were evaluated by laser-Doppler flowmetry. In experiment group, CCoBF increased together with the beginning of electrical stimulation (5 V, 0.5-ms impulse duration, square-shaped, 10-Hz frequency). The right and left hemisphere CCoBF values of stimulation period at 15s, 30s, 45s, 60s, 75s, and 90s were significantly higher than those of baseline and 105 and 120s (p < 0.05). The maximum increase in right and left CCoBF was 15.6% and 15.1% respectively. In post-stimulation period, the right CCoBF decreased gradually and returned to the baseline values at 120 s. In experiment groups, the CCoBF values of right hemisphere were comparable that of left hemisphereL (p > 0.05). This study demonstrated that the electrical stimulation of the trigeminal nerve's infraorbital branch via dental pulp increases the cortical right and left CCoBF under physiological conditions.

Keywords:

• cerebral blood flow
• cerebral vascular innervation
• dental pulp
• electrical stimulation
• trigeminal nerve