近日,美国科罗拉多大学的研究人员研究发现,猴子和人类相同功能的大脑区域在颅骨里的位置并不总是一样。研究结果发表在2月5日出版的Nature Methods杂志上。
先前的研究对照各物种的大脑,并假定人类大脑就是猴子大脑的放大版,而且所有的功能是由大脑结构类似的区域执行的。
为了检验这个观点,波士顿哈佛医学院的Wim Vanduffel 和比利时的天主教鲁汶大学的同事实验纳入了24位人和4只猕猴,并观察当实验对象观看不同类型的人(好、坏、丑等类型)大脑的反应。他们对比了个体间受到同样的感官刺激后大脑的反应,并且证实了个体的大脑区域有相似的功能。
人类和猴子的大脑脑电图大部分对应,但是大脑一些有类似功能的区域却在完全不同的地方。
研究团队表示,这项发现非常重要,这要求研究人员建立更准确地人类进化模式生物。“不能因为A和B在猴子的大脑里隔得近,就推断出在人类的大脑里也是这样。”Vanduffel说。(生物谷Bioon.com)
doi:10.1038/nmeth.1869
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Establishing homology between monkey and human brains
Tor D Wager & Tal Yarkoni
Recent decades have seen a massive scientific effort to identify the functional organization of the brain in both humans and non–human species. Work in humans and other species provides complementary insights: animal models provide unique opportunities for invasive study of biological mechanisms, but differences in brain organization across species are a major obstacle to the identification of functional homologies. As a result, human and animal work is all too often discussed in parallel, separate literature. In this issue of Nature Methods, Mantini and colleagues introduce a method for identifying cross-species homologies to the neuroscientist's arsenal1.
Their technique, interspecies activity correlation (ISAC), uses functional magnetic resonance imaging (fMRI) to identify brain regions in which humans and monkeys exposed to the same dynamic stimulus—a 30-minute clip from the movie The Good, the Bad and the Ugly—show correlated patterns of activity1 (Fig. 1). The premise is that homologous regions should have similar patterns of activity across species. For example, a brain region sensitive to a particular configuration of features, including visual motion, hands, faces, object and others, should show a similar time course of activity in both species—even if its anatomical location differs across species and even if the precise features that drive the area's neurons have not yet been specified.