Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, Texas 78712, USA.
J Comp Neurol. 2011 Dec 15;519(18):3599-639. doi: 10.1002/cne.22735.
All animals evaluate the salience of external stimuli and integrate them with internal physiological information into adaptive behavior. Natural and sexual selection impinge on these processes, yet our understanding of behavioral decision-making mechanisms and their evolution is still very limited. Insights from mammals indicate that two neural circuits are of crucial importance in this context: the social behavior network and the mesolimbic reward system. Here we review evidence from neurochemical, tract-tracing, developmental, and functional lesion/stimulation studies that delineates homology relationships for most of the nodes of these two circuits across the five major vertebrate lineages: mammals, birds, reptiles, amphibians, and teleost fish. We provide for the first time a comprehensive comparative analysis of the two neural circuits and conclude that they were already present in early vertebrates. We also propose that these circuits form a larger social decision-making (SDM) network that regulates adaptive behavior. Our synthesis thus provides an important foundation for understanding the evolution of the neural mechanisms underlying reward processing and behavioral regulation.
所有动物都会评估外部刺激的显著性，并将其与内部生理信息整合到适应性行为中。自然选择和性选择都会影响这些过程，但我们对行为决策机制及其进化的理解仍然非常有限。来自哺乳动物的研究表明，两个神经网络在这方面至关重要：社会行为网络和中脑边缘奖励系统。在这里，我们回顾了神经化学、追踪、发育和功能损伤/刺激研究的证据，这些证据描绘了这两个回路的大多数节点在五个主要脊椎动物谱系中的同源关系：哺乳动物、鸟类、爬行动物、两栖动物和硬骨鱼。我们首次对这两个神经网络进行了全面的比较分析，并得出结论，它们早在早期脊椎动物中就已经存在。我们还提出，这些回路构成了一个更大的社会决策（SDM）网络，调节适应性行为。因此，我们的综合研究为理解奖励处理和行为调节的神经机制进化提供了重要基础。
