title: The effects of acute stress-induced sleep disturbance on acoustic trauma-induced tinnitus in rats.
abstract: Chronic tinnitus is a debilitating condition and often accompanied by anxiety, depression, and sleep disturbance. It has been suggested that sleep disturbance, such as insomnia, may be a risk factor/predictor for tinnitus-related distress and the two conditions may share common neurobiological mechanisms. This study investigated whether acute stress-induced sleep disturbance could increase the susceptibility to acoustic trauma-induced tinnitus in rats. The animals were exposed to unilateral acoustic trauma 24 h before sleep disturbance being induced using the cage exchange method. Tinnitus perception was assessed behaviourally using a conditioned lick suppression paradigm 3 weeks after the acoustic trauma. Changes in the orexin system in the hypothalamus, which plays an important role in maintaining long-lasting arousal, were also examined using immunohistochemistry. Cage exchange resulted in a significant reduction in the number of sleep episodes and acoustic trauma-induced tinnitus with acoustic features similar to a 32 kHz tone at 100 dB. However, sleep disturbance did not exacerbate the perception of tinnitus in rats. Neither tinnitus alone nor tinnitus plus sleep disturbance altered the number of orexin-expressing neurons. The results suggest that acute sleep disturbance does not cause long-term changes in the number of orexin neurons and does not change the perception of tinnitus induced by acoustic trauma in rats.
authors.affiliation: Department of Pharmacology and Toxicology, School of Medical Sciences, University of Otago, P.O. Box 913, Dunedin 9016, New Zealand ; Brain Health Research Centre, University of Otago, Dunedin 9016, New Zealand.
authors.forename: Yiwen
authors.identifier: 0000-0002-2439-0715
authors.initials: Y
authors.lastname: Zheng
authors.affiliation: Department of Pharmacology and Toxicology, School of Medical Sciences, University of Otago, P.O. Box 913, Dunedin 9016, New Zealand ; Brain Health Research Centre, University of Otago, Dunedin 9016, New Zealand.
authors.forename: Lucy
authors.initials: L
authors.lastname: Stiles
authors.affiliation: Department of Pharmacology and Toxicology, School of Medical Sciences, University of Otago, P.O. Box 913, Dunedin 9016, New Zealand ; Brain Health Research Centre, University of Otago, Dunedin 9016, New Zealand.
authors.forename: Yi-Ting
authors.identifier: 0000-0002-6809-6526
authors.initials: YT
authors.lastname: Chien
authors.affiliation: Department of Pharmacology and Toxicology, School of Medical Sciences, University of Otago, P.O. Box 913, Dunedin 9016, New Zealand ; Brain Health Research Centre, University of Otago, Dunedin 9016, New Zealand.
authors.forename: Cynthia L
authors.initials: CL
authors.lastname: Darlington
authors.affiliation: Department of Pharmacology and Toxicology, School of Medical Sciences, University of Otago, P.O. Box 913, Dunedin 9016, New Zealand ; Brain Health Research Centre, University of Otago, Dunedin 9016, New Zealand.
authors.forename: Paul F
authors.initials: PF
authors.lastname: Smith
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D006317:Hearing Loss, Noise-Induced / Q000503:physiopathology; D047908:Intracellular Signaling Peptides and Proteins / Q000096:biosynthesis; D009474:Neurons / Q000378:metabolism* / Q000473:pathology; D009479:Neuropeptides / Q000096:biosynthesis; D000068797:Orexins; D051381:Rats; D012893:Sleep Wake Disorders / Q000235:genetics / Q000503:physiopathology*; D014012:Tinnitus / Q000503:physiopathology*
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; D009479:Neuropeptides; D000068797:Orexins