title: Nuclear size of c-Fos expression at the auditory brainstem is related to the time-varying nature of the acoustic stimuli.
abstract: Acoustic stimulation is known to induce c-Fos expression in the auditory system but how the expression might be related to the time-variance of the sound (e.g., steady or frequency-varying) is unclear. Here we measured morphometrically Fos-immunohistochemical stains at the auditory brainstem after exposing rats to a pure tone or a narrow-range frequency modulated (FM) sound for various durations (10, 30 or 90 min). Nuclear sizes of Fos-stains at the cochlear nucleus (CN) and inferior colliculus (IC) were estimated under microscope. Tone stimulation at the given frequency (9 kHz) induced Fos-expression at locations consistent with the tonotopic maps, and no clear difference in the spatial distribution of the Fos-stains was observed across stimuli. In general, more Fos-stains appeared after longer stimulations and most notably cell nuclei labeled with Fos-immunoreactivity were statistically larger in size under longer pure tone and FM tone stimulations. Findings suggest that Fos-expression mechanisms are related to the selective response of different subpopulations of neurons to sounds of different time-varying properties. Results support that the time-variance of acoustic stimulation should be considered in the interpretation of Fos-expression findings.
authors.affiliation: Department of Physiology, Medical College, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Hui-Pin
authors.initials: HP
authors.lastname: Lu
authors.forename: Shur-Tzu
authors.initials: ST
authors.lastname: Chen
authors.forename: Paul Wai-Fung
authors.initials: PW
authors.lastname: Poon
mesh_terms: D000161:Acoustic Stimulation; D000818:Animals; D001306:Auditory Pathways / Q000166:cytology / Q000378:metabolism; D001307:Auditory Perception / Q000502:physiology*; D001931:Brain Mapping; D002467:Cell Nucleus / Q000378:metabolism* / Q000648:ultrastructure; D048429:Cell Size; D017626:Cochlear Nucleus / Q000166:cytology / Q000378:metabolism*; D007150:Immunohistochemistry; D007245:Inferior Colliculi / Q000166:cytology / Q000378:metabolism*; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D016760:Proto-Oncogene Proteins c-fos / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011930:Reaction Time / Q000502:physiology; D013997:Time Factors
chemical_list: D016760:Proto-Oncogene Proteins c-fos