Mastication and Salivation

Abstract

We studied the relationship between mastication and salivation in cats anesthetized with urethane and chloralose. We investigated reflex salivation induced by taste, mechanical and thermal stimulation to the oral region in decerebrate cats by recording the volume of submandibular salivary secretion. Copious salivary secretion was induced when noxious thermal or mechanical stimuli were applied to the oral region. We also examined salivary secretion induced by electrical stimulation to the food intake regulating area and to the masticatory-related area in the suprabulbar structures (e.g. the lateral hypothalamic area, amygdala, coronal cortex and orbital cortex). Before immobilization, repetitive electrical stimulation of each area in these suprabulbar structures casued salivary secretion, often associated with rhythmical tongue and jaw movements resembling mastication. It was even possible to induce salivary secretion when the animals were immobilized.
      We confirmed that salivary secretion could be evoked reflexly in decerebrate animals, indicating that the medullary salivary nuclei is capable of acting as a center for reflex salivation. It is obvious, on the other hand, that suprabulbar structures act on the center in the brain stem, and that there is a close relationship between mastication and salivation.