Cholinergic Modulation of Stimulus-Specific Adaptation in the Inferior Colliculus

[EN] Neural encoding of an ever-changing acoustic environment is a complex and demanding process that depends on modulation by neuro-active substances. Some neurons of the inferior colliculus (IC) exhibit “stimulus-specific adaptation” (SSA), i.e., a decrease in their response to a repetitive sound,...

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Detalles Bibliográficos
Autores: Aguilar Ayala, Yaneri, Malmierca, Manuel S.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2015
País:España
Institución:Universidad de Salamanca (USAL)
Repositorio:GREDOS. Repositorio Institucional de la Universidad de Salamanca
OAI Identifier:oai:gredos.usal.es:10366/145535
Acceso en línea:http://hdl.handle.net/10366/145535
Access Level:acceso abierto
Palabra clave:Acetylcholine
Attention
Auditory
Micriontophoresis
Neuromodulators
SSA
3205.07 Neurología
Descripción
Sumario:[EN] Neural encoding of an ever-changing acoustic environment is a complex and demanding process that depends on modulation by neuro-active substances. Some neurons of the inferior colliculus (IC) exhibit “stimulus-specific adaptation” (SSA), i.e., a decrease in their response to a repetitive sound, but not to a rare one. Previous studies have demonstrated that acetylcholine (ACh) alters the frequency response areas of auditory neurons and therefore is important in the encoding of spectral information. Here, we address how microion-tophoretic application of ACh modulates SSA in the IC of the anesthetized rat. We found that ACh decreased SSA in IC eurons by increasing the response to the repetitive tone. This effect was mainly mediated by muscarinic receptors. The strength of the cholinergic modulation depended on the baseline SSA level, exerting its greatest effect on neurons with intermediate SSA responses across IC subdivisions. Our data demonstrate that the increased availability of ACh exerts transient functional changes in partially adapting IC neurons, enhancing the sensory encoding of the ongoing stimulation. This effect potentially contributes to the propagation of ascending sensory-evoked afferent activity through the thalamus en route to the cortex.