title: The spiral ganglion and Rosenthal's canal in beluga whales.
abstract: With the increase of human activity and corresponding increase in anthropogenic sounds in marine waters of the Arctic, it is necessary to understand its effect on the hearing of marine wildlife. We have conducted a baseline study on the spiral ganglion and Rosenthal's canal of the cochlea in beluga whales (Delphinapterus leucas) as an initial assessment of auditory anatomy and health. We present morphometric data on the length of the cochlea, number of whorls, neuron densities along its length, Rosenthal's canal length, and cross-sectional area, and show some histological results. In belugas, Rosenthal's canal is not a cylinder of equal cross-sectional area, but its cross-section is greatest near the apex of the basal whorl. We found systematic variation in the numbers of neurons along the length of the spiral ganglion, indicating that neurons are not dispersed evenly in Rosenthal's canal. These results provide data on functionally important structural parameters of the beluga ear. We observed no signs of acoustic trauma in our sample of beluga whales.
authors.affiliation: Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, Ohio, 44240.
authors.forename: Jennifer D
authors.initials: JD
authors.lastname: Sensor
authors.affiliation: Department of Wildlife Management, North Slope Borough, Barrow, Alaska, 99723.
authors.forename: Robert
authors.initials: R
authors.lastname: Suydam
authors.affiliation: Department of Wildlife Management, North Slope Borough, Barrow, Alaska, 99723.
authors.forename: John C
authors.initials: JC
authors.lastname: George
authors.affiliation: Department of Otology and Laryngology, Harvard Medical School, Boston, Massachusetts, 02115.|Eaton-Peabody Laboratories Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, 02114.
authors.forename: M C
authors.initials: MC
authors.lastname: Liberman
authors.affiliation: Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, Ohio, 44240.
authors.forename: Denise
authors.initials: D
authors.lastname: Lovano
authors.affiliation: Department of Anthropology, Kent State University, Kent, Ohio, 44240.
authors.forename: Mary Ann
authors.initials: MA
authors.lastname: Rhaganti
authors.affiliation: Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, Ohio, 44240.
authors.forename: Sharon
authors.initials: S
authors.lastname: Usip
authors.affiliation: Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, Ohio, 44240.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Vinyard
authors.affiliation: Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, Ohio, 44240.
authors.forename: J G M
authors.initials: JG
authors.lastname: Thewissen
mesh_terms: D000818:Animals; D050643:Beluga Whale / Q000033:anatomy & histology*; D009474:Neurons / Q000166:cytology; D013136:Spiral Ganglion / Q000166:cytology*
keywords: Cetacea; Delphinapterus leucas; Odontoceti; cochlea; hearing; inner ear