title: Meta-adaptation in the auditory midbrain under cortical influence.
abstract: Neural adaptation is central to sensation. Neurons in auditory midbrain, for example, rapidly adapt their firing rates to enhance coding precision of common sound intensities. However, it remains unknown whether this adaptation is fixed, or dynamic and dependent on experience. Here, using guinea pigs as animal models, we report that adaptation accelerates when an environment is re-encountered-in response to a sound environment that repeatedly switches between quiet and loud, midbrain neurons accrue experience to find an efficient code more rapidly. This phenomenon, which we term meta-adaptation, suggests a top-down influence on the midbrain. To test this, we inactivate auditory cortex and find acceleration of adaptation with experience is attenuated, indicating a role for cortex-and its little-understood projections to the midbrain-in modulating meta-adaptation. Given the prevalence of adaptation across organisms and senses, meta-adaptation might be similarly common, with extensive implications for understanding how neurons encode the rapidly changing environments of the real world.
authors.affiliation: University College London Ear Institute, 332 Gray's Inn Road, London WC1X 8EE, UK.|Southwark and Central Integrated Psychological Therapies Team, The Maudsley Hospital, South London and Maudsley NHS Foundation Trust, Denmark Hill, London SE5 8AZ, UK.
authors.forename: Benjamin L
authors.initials: BL
authors.lastname: Robinson
authors.affiliation: Department of Physiology, Anatomy, and Genetics, University of Oxford, South Parks Road, Oxford OX1 3QX, UK.|Department of Engineering Science, Institute of Biomedical Engineering, University of Oxford, Old Road Campus Research Building, Headington, Oxford OX3 7DQ, UK.
authors.forename: Nicol S
authors.initials: NS
authors.lastname: Harper
authors.affiliation: University College London Ear Institute, 332 Gray's Inn Road, London WC1X 8EE, UK.|The Australian Hearing Hub, Macquarie University, 16 University Avenue, Sydney, NSW 2109, Australia.
authors.forename: David
authors.initials: D
authors.lastname: McAlpine
mesh_terms: D000161:Acoustic Stimulation; D000222:Adaptation, Physiological; D000818:Animals; D001303:Auditory Cortex / Q000502:physiology; D001306:Auditory Pathways / Q000502:physiology*; D001307:Auditory Perception / Q000502:physiology*; D005260:Female; D006168:Guinea Pigs; D007036:Hypothermia, Induced; D008297:Male; D008636:Mesencephalon / Q000166:cytology / Q000502:physiology*; D023421:Models, Animal; D009474:Neurons / Q000502:physiology*