Bruce L L, Neary T J
Department of Biomedical Sciences, Creighton University, Omaha, NE 68178, USA.
Brain Behav Evol. 1995;46(4-5):224-34. doi: 10.1159/000113276.
Recent studies of the limbic system of tetrapods have made data available that challenge some of the long-held tenets of forebrain evolution. Using the basic principle of parsimony--that the best hypotheses concerning homologies are those requiring the fewest number of evolutionary changes--we have reevaluated comparisons of tetrapod limbic systems. Given the current data, the following points appear to be justified: (1) the common ancestors of reptiles and mammals had a well-developed limbic system in which the basic subdivisions and connections of the amygdalar nuclei were established; (2) the ventral part of the lateral pallium in amphibians appears to be a single structure which corresponds to at least four areas in reptiles: centromedial DVR, ventral anterior amygdala, lateral amygdala, and part of the lateral cortex; (3) the medial pallium in amphibians appears to be homologous with the dorsal and medial cortices in reptiles and with the general and hippocampal cortices in mammals: (4) the cortical targets of the main olfactory bulb in reptiles and mammals appear to be homologous, and their common ancestor probably had a corresponding olfactory pallial field; (5) the targets of the accessory olfactory bulb in amphibians, reptiles, and mammals appear to be homologous, with the exception of nucleus sphericus in reptiles, which lacks an obvious homologue in non-reptiles.
最近对四足动物边缘系统的研究提供了一些数据，这些数据对一些长期以来关于前脑进化的原则提出了挑战。利用简约性的基本原则——即关于同源性的最佳假设是那些需要最少进化变化数量的假设——我们重新评估了四足动物边缘系统的比较。根据目前的数据，以下几点似乎是合理的：（1）爬行动物和哺乳动物的共同祖先拥有一个发育良好的边缘系统，其中杏仁核的基本细分和连接已经建立；（2）两栖动物外侧皮质的腹侧部分似乎是一个单一结构，它对应于爬行动物中的至少四个区域：中央内侧背侧室周灰质、腹侧前杏仁核、外侧杏仁核和部分外侧皮质；（3）两栖动物的内侧皮质似乎与爬行动物的背侧和内侧皮质以及哺乳动物的一般皮质和海马皮质同源；（4）爬行动物和哺乳动物中主嗅球的皮质靶点似乎是同源的，它们的共同祖先可能有一个相应的嗅觉皮质区域；（5）两栖动物、爬行动物和哺乳动物中副嗅球的靶点似乎是同源的，但爬行动物中的球状核除外，它在非爬行动物中缺乏明显的同源物。
