Local inhibition of GABA affects precedence effect in the inferior colliculus
نویسندگان
چکیده
The precedence effect is a prerequisite for faithful sound localization in a complex auditory environment, and is a physiological phenomenon in which the auditory system selectively suppresses the directional information from echoes. Here we investigated how neurons in the inferior colliculus respond to the paired sounds that produce precedence-effect illusions, and whether their firing behavior can be modulated through inhibition with gamma-aminobutyric acid (GABA). We recorded extracellularly from 36 neurons in rat inferior colliculus under three conditions: no injection, injection with saline, and injection with gamma-aminobutyric acid. The paired sounds that produced precedence effects were two identical 4-ms noise bursts, which were delivered contralaterally or ipsilaterally to the recording site. The normalized neural responses were measured as a function of different inter-stimulus delays and half-maximal interstimulus delays were acquired. Neuronal responses to the lagging sounds were weak when the inter-stimulus delay was short, but increased gradually as the delay was lengthened. Saline injection produced no changes in neural responses, but after local gamma-aminobutyric acid application, responses to the lagging stimulus were suppressed. Application of gamma-aminobutyric acid affected the normalized response to lagging sounds, independently of whether they or the paired sounds were contralateral or ipsilateral to the recording site. These observations suggest that local inhibition by gamma-aminobutyric acid in the rat inferior colliculus shapes the neural responses to lagging sounds, and modulates the precedence effect.
منابع مشابه
Physiological measures of the precedence effect and spatial release from masking in the cat inferior colliculus
متن کامل
GABAergic inhibition controls neural gain in inferior colliculus neurons sensitive to interaural time differences.
We investigated the role of GABAergic inhibition on the responses of inferior colliculus (IC) neurons sensitive to interaural time differences (ITDs) in anesthetized guinea pigs. Responses to static and dynamic ITDs were obtained before, during, and after recovery from ionotophoretic application of GABA, or antagonists to the GABA(A) receptor gabazine and bicuculline. For most neurons, a linear...
متن کاملRole of GABAergic inhibition in the coding of interaural time differences of low-frequency sounds in the inferior colliculus.
A major cue for the localization of sound in space is the interaural time difference (ITD). We examined the role of inhibition in the shaping of ITD responses in the inferior colliculus (IC) by iontophoretically ejecting gamma-aminobutyric acid (GABA) antagonists and GABA itself using a multibarrel pipette. The GABA antagonists block inhibition, whereas the applied GABA provides a constant leve...
متن کاملChapter 1 . Signal Transmission in the Auditory System
Litovsky, R.Y., B.R. Cranston, and B. Delgutte. "Neural Correlates of the Precedence Effect in the Inferior Colliculus: Effect of Localization Cues." Abstracts of the Twenty-First Midwinter Research Meeting of the Association for Research in Otolaryngology, St. Petersburg Beach, Florida, February 15-19, 1998, p. 40.
متن کاملAge Related Loss of GABA Neurotransmittion in the Inferior Colliculus of the Rat: Implications for Presbycusis
12 (1986) p. 1280. 7 Faingold, C.P., Gehlbach, G. and Caspary, D.M., decreased Effectiveness of GABA-Mediated Inhibition in the Inferior Colliculus of the Genetically Epilepsy-Prone Rat., Exp Neurol, 93 (1986) pp. 145-159. 8 Faingold, C.L., Gehlbach, G. and Caspary, n.M., Effects of GABA on inferior colliculus neuronal responses to acoustic stimuli, Society for Neuroscience Abstract, 11 (1985) ...
متن کامل