AUDITORY AND VESTIBULAR SYSTEMSCortical mapping of auditory-evoked offset responses in ratsTakahashi, HirokazuCA; Nakao, Masayuki; Kaga, Kimitaka1Author Information Department of Engineering Synthesis, Graduate School of Engineering, The University of Tokyo, Tokyo, 113-8656, Japan 1Department of Otolaryngology, and Head and Neck Surgery, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan CACorresponding Author: email@example.com Received 6 April 2004; accepted 17 May 2004 NeuroReport: July 19th, 2004 - Volume 15 - Issue 10 - p 1565-1569 doi: 10.1097/01.wnr.0000134848.63755.5c Buy SDC Metrics Abstract We characterized the auditory-evoked offset responses of the rat auditory cortex by multiple-site surface microelectrode recording. Tone bursts served as test stimuli. Offset responses did not appear tonotopically, but at the fringe of tonotopic onset distributions. Offset amplitude was significantly sensitive to sound intensity, fall time at tone termination, and duration. These results suggest that offset responses are associated with inhibitory responses surrounding excitatory onset responses, and offset responses become large when inhibition becomes strong and long or terminates synchronously. Thus, the rebound after the inhibition in the presence of a stimulus is likely to be a major cause of offset responses in the auditory cortex. © 2004 Lippincott Williams & Wilkins, Inc.