"Prolonged sound exposure has different effects on increasing neuronal size in the auditory cortex and brainstem"Paul W.F. Poon 博士(台湾国立成功大学)-2014.5.8

时间：2014年5月8日 10:00

地点：脑功能基因组学教育部重点实验室一楼会议室

报告题目：Prolonged sound exposure has different effects on increasing neuronal size in the auditory cortex and brainstem

报告人：Paul W.F. Poon 博士 台湾国立成功大学

主持人：周晓明 教授

报告人简介：1979年获得美国Indiana University哲学博士学位，1994年起为台湾国立成功大学（National Cheng Kung University）生理学系教授。其研究工作主要采用单细胞电生理记录和免疫组织学技术，以大鼠听觉系统为模型，研究语音识别的神经基础和中枢语音识别的可塑性，以及新一代人工耳及助听器的开发，是一位具有丰硕研究成果的科学家。

报告简介：Tone, at moderate levels, presented to young rats in postnatal week 4 can enlarge neurons in the auditory cortex. It remains unclear whether this change occurs only in the cortex, or reflects a change taking place in the auditory brainstem. We compared sound-exposure effects on neuronal size in the auditory cortex and the midbrain. Starting from postnatal day 22, young rats were exposed to a low-frequency tone (4 kHz at 65 dB SPL) for a period of 3 (postnatal day 22 to 25) or 7 (postnatal day 22 to 29) days before being sacrificed. Neurons were analyzed morphometrically from 7 um-thick histological sections. After sound-exposure for 3 days, cell enlargement (perikaryon) was found in the high-frequency region of the auditory cortex away from the representation of the exposing tone with no similar change in the midbrain. After exposure for 7 days, cell enlargement (perikaryon and nucleus alike) was found in both the cortex and the midbrain which extended to all frequency regions. In the cortex, greater changes were again found in the high-frequency region. No changes in neuronal size were detected in the cochlear nucleus or the visual midbrain. Such differential effects of sound-exposure in the auditory centers across cortical and subcortical levels cannot be explained by a simple driven activity occurring earlier in the brainstem and might involve the function of other structures, for example, the descending auditory system