以田鼠作为动物模型来研究社会行为的进化:基因、脑与行为

摘要

田鼠属的一些近缘种间具有独特的社会行为多态性.例如Microtus ochrogaster和M.pinetorum为一夫一妻制,而M.montanus和M.pennsylvanicus则为独居和一夫多妻制.无论是在野外还是人工饲养的条件下,单配制的田鼠其雌、雄成年个体一经交配即在两者之间形成长期的配偶关系并且双亲共同哺育后代.已证明神经多肽加压素(Vasopressin)参与了田鼠单配制行为的神经调控.本篇综述了过去以及近期关于加压素调控田鼠配偶关系形成的研究结果和进展.首先,阐述了加压素V1a受体(V1aR)在脑分布的种间差异,并以此来鉴别特定脑区在配偶关系形成中的功能;其次,探讨了运用V1aR拮抗物的药理学方法来决定究竟哪些脑区参与配偶关系的形成,还描述了田鼠种间V1aR基因结构和功能的不同,以及这些不同对V1aR在大脑的分布和行为调控潜在的作用机制;最后,讨论了最新的研究结果,即对一夫多妻制田鼠进行脑V1aR基因的改造,从而使之表现出一夫一妻制田鼠的行为.总之,了解复杂的社会性行为的遗传和神经机制可以加深我们对种间和种内行为分歧进化的理解[动物学报50(4):479-489,2004].%The vole genus Microtus shows extraordinary diversity in the range of social behaviors among closely related species. A few species, such as Microtus ochrogaster and pinetorum (prairie and pine vole), show monogamous social organization, while other species such as Microtus montanus and pennsylvanicus (montane and meadow vole) are solitary and promiscuous. Monogamous prairie and pine voles display selective and long-lasting pair bond formation between adult mates and biparental care of the offspring both in nature as well as in the laboratory. The neuropeptide vasopressin is involved in the neural regulation of monogamous behavior in vole species. Here, we review the past and current findings related to the vasopressin system and pair bond formation in voles. First, we review vole species differences in the distribution of vasopressin V1a receptors (V1aR) in the brain as a means to identify the role of specific brain regions in pair bond formation. Next, we discuss pharmacological manipulations with V1aR antagonist administered into specific brain regions to determine which regions are necessary for pair bond formation. We also describe vole species differences in V1aR gene structure and function and potential contribution to species differences in V1aR brain distribution and behavior. Lastly,we discuss novel findings in which gene manipulation of brain V1aR in a promiscuous vole species confers monogamous behavior. Thoroughly understanding the genetic and neural mechanisms underlying a complex social behavior can have significant implications for understanding the evolution of diverse behavior between and within species [ Acta Zoologica Sinica50 (4): 479-489, 2004].