Avey Marc T, Phillmore Leslie S, MacDougall-Shackleton Scott A
Department of Psychology, University of Western Ontario, London, Ont. N6A 5C2, Canada.
Behav Brain Res. 2005 Dec 7;165(2):247-53. doi: 10.1016/j.bbr.2005.07.002. Epub 2005 Aug 10.
Sensory driven immediate early gene expression (IEG) has been a key tool to explore auditory perceptual areas in the avian brain. Most work on IEG expression in songbirds such as zebra finches has focused on playback of acoustic stimuli and its effect on auditory processing areas such as caudal medial mesopallium (CMM) caudal medial nidopallium (NCM). However, in a natural setting, the courtship displays of songbirds (including zebra finches) include visual as well as acoustic components. To determine whether the visual stimulus of a courting male modifies song-induced expression of the IEG ZENK in the auditory forebrain we exposed male and female zebra finches to acoustic (song) and visual (dancing) components of courtship. Birds were played digital movies with either combined audio and video, audio only, video only, or neither audio nor video (control). We found significantly increased levels of Zenk response in the auditory region CMM in the two treatment groups exposed to acoustic stimuli compared to the control group. The video only group had an intermediate response, suggesting potential effect of visual input on activity in these auditory brain regions. Finally, we unexpectedly found a lateralization of Zenk response that was independent of sex, brain region, or treatment condition, such that Zenk immunoreactivity was consistently higher in the left hemisphere than in the right and the majority of individual birds were left-hemisphere dominant.
感觉驱动的即刻早期基因表达（IEG）一直是探索鸟类大脑听觉感知区域的关键工具。大多数关于斑胸草雀等鸣禽IEG表达的研究都集中在声音刺激的回放及其对听觉处理区域的影响，如尾内侧中脑皮质（CMM）和尾内侧巢皮质（NCM）。然而，在自然环境中，鸣禽（包括斑胸草雀）的求偶展示包括视觉和听觉成分。为了确定求偶雄性的视觉刺激是否会改变听觉前脑中IEG ZENK的歌声诱导表达，我们让雄性和雌性斑胸草雀接触求偶的听觉（歌声）和视觉（舞蹈）成分。给鸟类播放数字电影，电影内容包括音频和视频结合、仅音频、仅视频或既无音频也无视频（对照）。我们发现，与对照组相比，暴露于声音刺激的两个处理组中，听觉区域CMM的Zenk反应水平显著增加。仅视频组的反应处于中间水平，表明视觉输入对这些听觉脑区的活动有潜在影响。最后，我们意外地发现了Zenk反应的一种偏侧化现象，这种偏侧化与性别、脑区或处理条件无关，即Zenk免疫反应性在左半球始终高于右半球，并且大多数个体鸟类以左半球为主。
