Lesions of the ventral ascending noradrenergic bundles decrease the stress response to occlusal disharmony in rats

► We investigated the relationship between the response of the hypothalamic-pituitary-adrenal axis and the ventral ascending noradrenergic bundles in rats with occlusal disharmony. ► We examined changes in extracellular noradrenaline in the hypothalamic paraventricular nucleus and plasma corticosterone following occlusal disharmony in rats injected with 6-hydroxydopamine. ► 6-hydroxydopamine microinjection into the ventral ascending noradrenergic bundles reduced the magnitude of the responses of extracellular noradrenaline in the paraventricular nucleus and the plasma corticosterone to occlusal disharmony.