Ladage Lara D, Riggs Becky J, Sinervo Barry, Pravosudov Vladimir V
University of Nevada, Reno Biology Department.
Anim Behav. 2009 Jul 1;78(1):91-96. doi: 10.1016/j.anbehav.2009.03.020.
Spatial abilities have been associated with many ecologically-relevant behaviors such as territoriality, mate choice, navigation and acquisition of food resources. Differential demands on spatial abilities in birds and mammals have been shown to affect the hippocampus, the region of the brain responsible for spatial processing. In some bird and mammal species, higher demands on spatial abilities are associated with larger hippocampal volumes. The medial and dorsal cortices are the putative reptilian homologues of the mammalian hippocampus, yet few studies have examined the relationship between these brain areas and differential spatial use strategies in reptiles. Further, many studies in birds and mammals compare hippocampal attributes between species that utilize space differently, potentially confounding species-specific effects with effects due to differential behaviors in spatial use. Here, we investigated the relationship between spatial use strategies and medial and dorsal cortical volumes in males of the side-blotched lizard (Uta stansburiana). In this species, males occur in three different morphs, each morph using different spatial niches: large territory holders, small territory holders and non-territory holders with home ranges smaller than the territories of small territory holders. We found that large territory holders had larger dorsal cortical volumes relative to the remainder of the telencephalon compared with non-territorial males, and small territory holders were intermediate. These results suggest that some aspect of holding a large territory may place demands on spatial abilities, which is reflected in a brain region thought partially responsible for spatial processing.
空间能力与许多与生态相关的行为有关，如领地行为、配偶选择、导航和获取食物资源。研究表明，鸟类和哺乳动物对空间能力的不同需求会影响海马体，即大脑中负责空间处理的区域。在一些鸟类和哺乳动物物种中，对空间能力的更高需求与更大的海马体体积相关。内侧和背侧皮质被认为是哺乳动物海马体的爬行类同源物，但很少有研究探讨这些脑区与爬行动物不同空间利用策略之间的关系。此外，许多关于鸟类和哺乳动物的研究比较了不同空间利用方式的物种之间的海马体特征，这可能会将物种特异性效应与空间利用差异行为所产生的效应混淆。在这里，我们研究了雄性西部侧斑鬣蜥（Uta stansburiana）的空间利用策略与内侧和背侧皮质体积之间的关系。在这个物种中，雄性有三种不同的形态，每种形态使用不同的空间生态位：大领地占有者、小领地占有者和活动范围小于小领地占有者领地的非领地占有者。我们发现，与非领地雄性相比，大领地占有者相对于端脑的其余部分具有更大的背侧皮质体积，小领地占有者则介于两者之间。这些结果表明，占据大领地的某些方面可能对空间能力提出了要求，这反映在一个被认为部分负责空间处理的脑区中。
