Efferent Chorda Tympani Activity and Salivary Secretion in the Rat

Abstract

Abstract It is known that nerve impulses to the mandibular salivary gland must be carried in the chorda tympani proper nerve, although they have never been recorded. This study presents recordings of efferent impulses in this nerve and simultaneous observations of secretion from this gland in rats under neuroleptic analgesia, during electrical stimulation of he salivary nuclei in the brainstem. Stimulation was found to increase the impulse activity in the nerve and to lead to secretion of saliva. The secretion ceased when the nerve was blocked. The relationship was best described by a straight line plot of the logarithm of the increased nerve activity against secretion, the correlation coefficient being 0.84. Barbiturate abolished the effect of brain stimulation. This indicates that nuclear structures, and not chorda tympani fibres, were being stimulated.