کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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4326766 | 1614092 | 2010 | 9 صفحه PDF | دانلود رایگان |
The immediate-early-gene c-fos is among the first genes to be expressed following sensory-invoked neuronal activity. Its gene product c-Fos forms the limiting monomer of the heterodimeric activator protein-1 transcription factor that triggers various genes involved in neuroplastic remodeling. This study investigated the pattern of c-Fos expression in anteroventral (AVCN) and dorsal cochlear nucleus (DCN) and central inferior colliculus (CIC) after 45 min, 73 min, 2 h, 3:15 h and 5 h of unilateral electrical intracochlear stimulation (EIS) at 50 Hz in anaesthetized rats. Following EIS, tonotopic c-Fos expression was observed for each stimulation time in ipsilateral AVCN, DCN bilaterally, and contralateral CIC. By counting c-Fos positive nuclei, we discovered temporal non-linearities in the size of the respective population of c-Fos expressing neurons. In all regions investigated, the populations significantly increased from 73 min to 2 h but decreased towards 3:15 h. In AVCN, the number rose again by 5 h of EIS. Remarkably, the same was noted for neurons with large nuclei in deep DCN. In both regions, the population of responsive neurons shifted spatially: In central AVCN, the density of c-Fos positive cells increased significantly from 2 to 5 h with medial and lateral regions remaining unchanged. In DCN, the density of large c-Fos positive nuclei fell in the upper and rose in the deep layers from 45 min to 5 h of EIS. In conclusion, spatiotemporally varying recruitments of neuronal subpopulations into cellular networks responding to specific patterns of sensory activity take place in the auditory brainstem.
Journal: Brain Research - Volume 1347, 6 August 2010, Pages 33–41