title: Selective Attention to Visual Stimuli Using Auditory Distractors Is Altered in Alpha-9 Nicotinic Receptor Subunit Knock-Out Mice.
abstract: During selective attention, subjects voluntarily focus their cognitive resources on a specific stimulus while ignoring others. Top-down filtering of peripheral sensory responses by higher structures of the brain has been proposed as one of the mechanisms responsible for selective attention. A prerequisite to accomplish top-down modulation of the activity of peripheral structures is the presence of corticofugal pathways. The mammalian auditory efferent system is a unique neural network that originates in the auditory cortex and projects to the cochlear receptor through the olivocochlear bundle, and it has been proposed to function as a top-down filter of peripheral auditory responses during attention to cross-modal stimuli. However, to date, there is no conclusive evidence of the involvement of olivocochlear neurons in selective attention paradigms. Here, we trained wild-type and α-9 nicotinic receptor subunit knock-out (KO) mice, which lack cholinergic transmission between medial olivocochlear neurons and outer hair cells, in a two-choice visual discrimination task and studied the behavioral consequences of adding different types of auditory distractors. In addition, we evaluated the effects of contralateral noise on auditory nerve responses as a measure of the individual strength of the olivocochlear reflex. We demonstrate that KO mice have a reduced olivocochlear reflex strength and perform poorly in a visual selective attention paradigm. These results confirm that an intact medial olivocochlear transmission aids in ignoring auditory distraction during selective attention to visual stimuli.
  
  
  
  The auditory efferent system is a neural network that originates in the auditory cortex and projects to the cochlear receptor through the olivocochlear system. It has been proposed to function as a top-down filter of peripheral auditory responses during attention to cross-modal stimuli. However, to date, there is no conclusive evidence of the involvement of olivocochlear neurons in selective attention paradigms. Here, we studied the behavioral consequences of adding different types of auditory distractors in a visual selective attention task in wild-type and α-9 nicotinic receptor knock-out (KO) mice. We demonstrate that KO mice perform poorly in the selective attention paradigm and that an intact medial olivocochlear transmission aids in ignoring auditory distractors during attention.
authors.affiliation: Programa de Fisiología y Biofísica, ICBM, Facultad de Medicina, Universidad de Chile, Santiago 8380453, Chile.
authors.forename: Gonzalo
authors.identifier: 0000-0002-0227-7578
authors.initials: G
authors.lastname: Terreros
authors.affiliation: Programa de Fisiología y Biofísica, ICBM, Facultad de Medicina, Universidad de Chile, Santiago 8380453, Chile.
authors.forename: Pascal
authors.initials: P
authors.lastname: Jorratt
authors.affiliation: Programa de Fisiología y Biofísica, ICBM, Facultad de Medicina, Universidad de Chile, Santiago 8380453, Chile, Departamento de Tecnología Médica, Facultad de Medicina, Universidad de Chile, Santiago 8380455, Chile.
authors.forename: Cristian
authors.identifier: 0000-0001-6971-1685
authors.initials: C
authors.lastname: Aedo
authors.affiliation: Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Dr. Héctor N. Torres, Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires 1428, Argentina, and Instituto de Farmacología, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires 1122, Argentina.
authors.forename: Ana Belén
authors.identifier: 0000-0001-9487-0311
authors.initials: AB
authors.lastname: Elgoyhen
authors.affiliation: Programa de Fisiología y Biofísica, ICBM, Facultad de Medicina, Universidad de Chile, Santiago 8380453, Chile, Departamento de Otorrinolaringología, Hospital Clínico de la Universidad de Chile, Santiago 8380456, Chile, pdelano@med.uchile.cl.
authors.forename: Paul H
authors.identifier: 0000-0003-2588-4757
authors.initials: PH
authors.lastname: Delano
mesh_terms: D000161:Acoustic Stimulation; D000704:Analysis of Variance; D000818:Animals; D001288:Attention / Q000502:physiology*; D001306:Auditory Pathways / Q000502:physiology*; D001307:Auditory Perception / Q000502:physiology*; D002755:Choice Behavior / Q000502:physiology*; D003056:Cochlear Nerve / Q000502:physiology; D004569:Electroencephalography; D016057:Evoked Potentials, Auditory, Brain Stem / Q000235:genetics / Q000502:physiology*; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D010775:Photic Stimulation; D011978:Receptors, Nicotinic / Q000172:deficiency* / Q000235:genetics; D013997:Time Factors
chemical_list: C402445:Chrna9 protein, mouse; D011978:Receptors, Nicotinic
keywords: attention; auditory distractors; auditory efferent; nicotinic receptors; olivocochlear; top-down