AUDITORY AND VESTIBULAR SYSTEMSGABA-A antagonist causes dramatic expansion of tuning in primary auditory cortexWang, Jian1; Caspary, Donald2; Salvi, Richard J.1,3Author Information 1Hearing Research Laboratory, 215 Parker Hall, University at Buffalo, Buffalo, NY 14214 2Department of Pharmacology, Southern Illinois University Medical School, Springfield, IL 62794–9230, USA 3Corresponding Author: Richard J. Salvi Acknowledgments: Supported by NIH grant P01 DC03600-01A1. Received 12 January 2000; accepted 30 January 2000 NeuroReport: April 7, 2000 - Volume 11 - Issue 5 - p 1137-1140 Buy Abstract Responses from 80 neurons in primary auditory cortex of anesthetized chinchillas were investigated before and during iontophoresis of bicuculline (BIC), a GABA-A antagonist. BIC caused a significant increase in the spontaneous discharge rate (SR) and driven firing rate in most neurons. Threshold decreased in many neurons and the excitatory response area expanded significantly above and below the neuron's characteristic frequency (CF). These results indicate that many neurons in primary auditory cortex receive excitatory inputs from a much broader frequency range than previously believed. GABA-A mediated inhibition can significantly alter the excitability and tuning of auditory cortex and could contribute significantly to cortical plasticity due to experience and cochlear pathology. © 2000 Lippincott Williams & Wilkins, Inc.