title: Lesions of the ventral ascending noradrenergic bundles decrease the stress response to occlusal disharmony in rats.
abstract: Occlusal disharmony induced by placing an acryl cap on the lower incisors of rats is perceived as chronic stress. This chronic stress activates corticotropin-releasing hormone (CRH) neurons in the hypothalamic paraventricular nucleus (PVN), resulting in stimulation of the hypothalamic-pituitary-adrenal (HPA) axis. The ventral ascending noradrenergic bundles (V-NAB) from the brainstem innervate the PVN. To investigate the relationship between the response of the HPA axis and the V-NAB, we examined changes in extracellular noradrenaline (NA) in the PVN and plasma corticosterone, the final output of the HPA axis, following occlusal disharmony in rats injected with 6-hydroxydopamine (6-OHDA), a specific catecholamine neurotoxin. 6-OHDA microinjection into the V-NAB reduced the magnitude of the responses of extracellular NA in the PVN and the plasma corticosterone to occlusal disharmony. Our results suggest that V-NAB to the PVN are involved in occlusal disharmony-induced activation of the HPA axis.
authors.affiliation: Division of Pediatric Dentistry, Department of Oral Functional Science, Hokkaido University Graduate School of Dental Medicine, North 13, West 7, Kita-ku, Sapporo 060-8586, Japan. tyoshi03@den.hokudai.ac.jp
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Yoshihara
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Yawaka
mesh_terms: D000818:Animals; D003345:Corticosterone / Q000097:blood; D004195:Disease Models, Animal; D004563:Electrochemistry; D008297:Male; D008310:Malocclusion / Q000139:chemically induced / Q000601:surgery; D008526:Medulla Oblongata / Q000187:drug effects / Q000502:physiology; D017551:Microdialysis; D009434:Neural Pathways / Q000187:drug effects / Q000378:metabolism; D009638:Norepinephrine / Q000378:metabolism*; D016627:Oxidopamine / Q000633:toxicity; D010286:Paraventricular Hypothalamic Nucleus / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013315:Stress, Psychological / Q000150:complications* / Q000473:pathology*; D013997:Time Factors
chemical_list: D016627:Oxidopamine; D003345:Corticosterone; D009638:Norepinephrine