title: Excitatory and inhibitory tonotopic bands in chinchilla inferior colliculus revealed by c-fos immuno-labeling.
abstract: We describe in detail a reliable experimental protocol for c-fos immuno-labeling of patterns of neural activation in the chinchilla (chinchilla laniger). We report on resting-level neural activity in inferior colliculus (IC) of auditory midbrain, and on tonotopic bands present following 90 min of pure-tone sound stimulation. Neurons activated by 6-kHz sound stimulation lay ventro-medial to those activated at 2 kHz. This is consistent with the known tonotopic organization of IC, and verified in the present report by multi-unit neuron response recordings in central nucleus of IC. Of particular interest, we observe a significant reduction in cell labeling adjacent to the tonotopic bands, and suggest that such decreases represent inhibitory regions. C-fos-labeled bands and lateral regions of reduced labeling resemble excitatory and lateral-inhibitory response areas of IC neurons.
authors.affiliation: Department of Physiology, University of Toronto, Toronto M5S 1A8, Canada; Institute of Biomaterials & Biomedical Engineering, University of Toronto, Toronto M5S 3G9, Canada; The Auditory Science Laboratory, Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto M5G 1X8, Canada. Electronic address: L.dalessandro@utoronto.ca.
authors.forename: Lisa M
authors.initials: LM
authors.lastname: D'Alessandro
authors.affiliation: Department of Physiology, University of Toronto, Toronto M5S 1A8, Canada; Institute of Biomaterials & Biomedical Engineering, University of Toronto, Toronto M5S 3G9, Canada; Department of Otolaryngology, Head and Neck Surgery, University of Toronto, Toronto M5G 2N2, Canada; The Auditory Science Laboratory, Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto M5G 1X8, Canada. Electronic address: rvh@sickkids.ca.
authors.forename: Robert V
authors.initials: RV
authors.lastname: Harrison
mesh_terms: D000161:Acoustic Stimulation; D000162:Acoustics; D000818:Animals; D001306:Auditory Pathways / Q000502:physiology; D002682:Chinchilla; D017626:Cochlear Nucleus / Q000502:physiology; D004594:Electrophysiology; D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology*; D005260:Female; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry / Q000379:methods*; D007245:Inferior Colliculi / Q000502:physiology*; D008297:Male; D008636:Mesencephalon / Q000473:pathology; D009474:Neurons / Q000378:metabolism / Q000502:physiology; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism*
chemical_list: D016760:Proto-Oncogene Proteins c-fos