Skip to main content

Research Repository

Advanced Search

Reductions in cortical alpha activity, enhancements in neural responses and impaired gap detection caused by sodium salicylate in awake guinea pigs

Berger, Joel I.; Coomber, Ben; Wallace, Mark N.; Palmer, Alan R.

Authors

Joel I. Berger Joel.Berger@nottingham.ac.uk

Ben Coomber Ben.Coomber@nottingham.ac.uk

Alan R. Palmer alan.palmer@nottingham.ac.uk



Abstract

Tinnitus chronically affects between 10–15% of the population but, despite its prevalence, the underlying mechanisms are still not properly understood. One experimental model involves administration of high doses of sodium salicylate, as this is known to reliably induce tinnitus in both humans and animals. Guinea pigs were implanted with chronic electrocorticography (ECoG) electrode arrays, with silver-ball electrodes placed on the dura over left and right auditory cortex. Two more electrodes were positioned over the cerebellum to monitor auditory brainstem responses (ABRs). We recorded resting-state and auditory evoked neural activity from awake animals before and 2 h following salicylate administration (350 mg/kg; i.p.). Large increases in click-evoked responses (> 100%) were evident across the whole auditory cortex, despite significant reductions in wave I ABR amplitudes (in response to 20 kHz tones), which are indicative of auditory nerve activity. In the same animals, significant decreases in 6–10 Hz spontaneous oscillations (alpha waves) were evident over dorsocaudal auditory cortex. We were also able to demonstrate for the first time that cortical evoked potentials can be inhibited by a preceding gap in background noise [gap-induced pre-pulse inhibition (PPI)], in a similar fashion to the gap-induced inhibition of the acoustic startle reflex that is used as a behavioural test for tinnitus. Furthermore, 2 h following salicylate administration, we observed significant deficits in PPI of cortical responses that were closely aligned with significant deficits in behavioural responses to the same stimuli. Together, these data are suggestive of neural correlates of tinnitus and oversensitivity to sound (hyperacusis).

Citation

Berger, J. I., Coomber, B., Wallace, M. N., & Palmer, A. R. (2017). Reductions in cortical alpha activity, enhancements in neural responses and impaired gap detection caused by sodium salicylate in awake guinea pigs. European Journal of Neuroscience, 45(3), https://doi.org/10.1111/ejn.13474

Journal Article Type Article
Acceptance Date Nov 7, 2016
Online Publication Date Nov 28, 2016
Publication Date Feb 1, 2017
Deposit Date Jan 24, 2017
Publicly Available Date Jan 24, 2017
Journal European Journal of Neuroscience
Print ISSN 0953-816X
Electronic ISSN 1460-9568
Publisher Wiley
Peer Reviewed Peer Reviewed
Volume 45
Issue 3
DOI https://doi.org/10.1111/ejn.13474
Keywords behaviour, chronic recordings, electrocorticography, hyperacusis, tinnitus
Public URL http://eprints.nottingham.ac.uk/id/eprint/40032
Publisher URL http://onlinelibrary.wiley.com/doi/10.1111/ejn.13474/abstract
Copyright Statement Copyright information regarding this work can be found at the following address: http://creativecommons.org/licenses/by/4.0

Files


Berger_et_al_2016-EJN.pdf (2.2 Mb)
PDF

Copyright Statement
Copyright information regarding this work can be found at the following address: http://creativecommons.org/licenses/by/4.0





You might also like



Downloadable Citations