title: The effects of repetitive transcranial magnetic stimulation in an animal model of tinnitus.
abstract: Tinnitus (phantom auditory perception associated with hearing loss) can seriously affect wellbeing. Its neural substrate is unknown however it has been linked with abnormal activity in auditory pathways. Though no cure currently exists, repetitive transcranial magnetic stimulation (rTMS) has been shown to reduce tinnitus in some patients, possibly via induction of cortical plasticity involving brain derived neurotrophic factor (BDNF). We examined whether low intensity rTMS (LI-rTMS) alleviates signs of tinnitus in a guinea pig model and whether this involves changes in BDNF expression and hyperactivity in inferior colliculus. Acoustic trauma was used to evoke hearing loss, central hyperactivity and tinnitus. When animals developed tinnitus, treatment commenced (10 sessions of 10 minutes 1 Hz LI-rTMS or sham over auditory cortex over 14 days). After treatment ceased animals were tested for tinnitus, underwent single-neuron recordings in inferior colliculus to assess hyperactivity and samples from cortex and inferior colliculus were taken for BDNF ELISA. Analysis revealed a significant reduction of tinnitus after LI-rTMS compared to sham, without a statistical significant effect on BDNF levels or hyperactivity. This suggests that LI-rTMS alleviates behavioural signs of tinnitus by a mechanism independent of inferior colliculus hyperactivity and BDNF levels and opens novel therapeutic avenues for tinnitus treatment.
authors.affiliation: The Auditory Laboratory, School of Anatomy, Physiology and Human Biology, The University of Western Australia, 35 Stirling Highway, Crawley WA 6009, Australia.
authors.forename: Wilhelmina H A M
authors.initials: WH
authors.lastname: Mulders
authors.affiliation: The Auditory Laboratory, School of Anatomy, Physiology and Human Biology, The University of Western Australia, 35 Stirling Highway, Crawley WA 6009, Australia.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Vooys
authors.affiliation: School of Animal Biology, The University of Western Australia, 35 Stirling Highway, Crawley WA 6009, Australia.
authors.forename: Kalina
authors.initials: K
authors.lastname: Makowiecki
authors.affiliation: School of Animal Biology, The University of Western Australia, 35 Stirling Highway, Crawley WA 6009, Australia.
authors.forename: Alex D
authors.initials: AD
authors.lastname: Tang
authors.affiliation: School of Animal Biology, The University of Western Australia, 35 Stirling Highway, Crawley WA 6009, Australia.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Rodger
mesh_terms: D000818:Animals; D019208:Brain-Derived Neurotrophic Factor / Q000096:biosynthesis*; D004195:Disease Models, Animal; D006168:Guinea Pigs; D006801:Humans; D055909:Magnetic Field Therapy; D003336:Tectum Mesencephali / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D014012:Tinnitus / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology / Q000628:therapy
chemical_list: D019208:Brain-Derived Neurotrophic Factor