Gobes Sharon M H, Bolhuis Johan J
Behavioural Biology and Helmholtz Institute, Utrecht University, Padualaan 8, P.O. Box 80086, 3508 TB Utrecht, The Netherlands.
Curr Biol. 2007 May 1;17(9):789-93. doi: 10.1016/j.cub.2007.03.059. Epub 2007 Apr 12.
Songbirds learn their song from an adult conspecific tutor when they are young, much like the acquisition of speech in human infants. When an adult zebra finch is re-exposed to its tutor's song, there is increased neuronal activation in the caudomedial nidopallium (NCM), the songbird equivalent of the auditory association cortex. This neuronal activation is related to the fidelity of song imitation, suggesting that the NCM may contain the neural representation of song memory. We found that bilateral neurotoxic lesions to the NCM of adult male zebra finches impaired tutor-song recognition but did not affect the males' song production or their ability to discriminate calls. These findings demonstrate that the NCM performs an essential role in the representation of tutor-song memory. In addition, our results show that tutor-song memory and a motor program for the bird's own song have separate neural representations in the songbird brain. Thus, in both humans and songbirds, the cognitive systems of vocal production and auditory recognition memory are subserved by distinct brain regions.
鸣禽在幼小时从成年同种导师那里学习它们的歌声，这很像人类婴儿学习语言。当成年斑胸草雀再次接触其导师的歌声时，在丘脑内侧巢皮质（NCM）中会出现神经元激活增加，NCM相当于鸣禽的听觉联合皮层。这种神经元激活与歌声模仿的保真度有关，这表明NCM可能包含歌声记忆的神经表征。我们发现，对成年雄性斑胸草雀的NCM进行双侧神经毒性损伤会损害对导师歌声的识别，但不会影响雄性的歌声产生或它们区分叫声的能力。这些发现表明，NCM在导师歌声记忆的表征中起着至关重要的作用。此外，我们的结果表明，导师歌声记忆和鸟类自身歌声的运动程序在鸣禽大脑中有独立的神经表征。因此，在人类和鸣禽中，发声产生和听觉识别记忆的认知系统都由不同的脑区提供支持。
