title: Short-term galvanic vestibular stimulation promotes functional recovery and neurogenesis in unilaterally labyrinthectomized rats.
abstract: Current experimental research on the therapeutic effects of galvanic vestibular stimulation (GVS) has mainly focused on neurodegenerative disorders. However, it primarily stimulates the vestibular nuclei and could be potentially effective in modulating imbalance between them in the case of unilateral labyrinthectomy (UL). Fifty male Wistar rats (180-220g) were used in 5 groups of 10: intact, sham, right-UL (RUL; without intervention), and two other right-UL groups with GVS intervention [one group treated with low rate GVS (GVS.LF; 6-7Hz), and the other treated with high rate GVS (GVS.HF; 17-18Hz)]. The UL models were prepared by intratympanic injection of sodium arsanilate. GVS protocols were implemented 30min/day and continued for 14 days via ring-shaped copper electrodes inserted subcutaneously over each mastoid. Functional recovery was assessed by several postural tests including support surface area, landing and air-righting reflexes, and rotarod procedure. Immunohistochemical investigations were performed on ipsi- and contra-lesional medial vestibular nuclei (MVN) using bromodeoxyuridine (BrdU) and Ki67, as markers of cell proliferation. Behavioral evaluations showed significant functional recovery of GVS-treated groups compared to RUL group. The percent of marked cells with BrdU and Ki67 were significantly higher in the ipsilesional MVN of both GVS-treated groups compared with other groups. Our findings confirmed the effectiveness of GVS-intervention in accelerating static and dynamic vestibular compensation. This could be explained by the cell proliferation in ipsilesional MVN cells and rapid rebalancing of the VNs and the modulation of their motor outputs. Therefore, GVS could be promising for rehabilitating patients with unilateral vestibular weakness.
authors.affiliation: Audiology Department, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran.
authors.forename: Moslem
authors.initials: M
authors.lastname: Shaabani
authors.affiliation: Audiology Department, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran. Electronic address: yones1333@gmail.com.
authors.forename: Yones
authors.initials: Y
authors.lastname: Lotfi
authors.affiliation: Department of Physiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Seyed Morteza
authors.initials: SM
authors.lastname: Karimian
authors.affiliation: Biostatistics Department, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Rahgozar
authors.affiliation: Department of Physiology, Medical School, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Hooshmandi
mesh_terms: D000818:Animals; D001973:Bromodeoxyuridine / Q000494:pharmacology; D004558:Electric Stimulation / Q000379:methods*; D008297:Male; D055495:Neurogenesis / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D020127:Recovery of Function / Q000502:physiology; D012677:Sensation; D014726:Vestibular Nuclei / Q000502:physiology; D014722:Vestibule, Labyrinth / Q000378:metabolism / Q000502:physiology*
chemical_list: D001973:Bromodeoxyuridine
keywords: BrdU; Galvanic; Labyrinthectomy; Neurogenesis; Rat; Vestibular