Causes and consequences of variation in the hippocampus of individuals utilizing different spatial strategies

空间记忆的使用与领地、配偶选择、导航和获取食物资源等行为有关。对空间能力的不同需求已被证明会影响海马体，这是大脑中被认为部分负责空间处理的区域。尽管许多研究发现空间利用策略与海马体结构之间存在正相关，但对海马体变异的原因以及遗传、经验、荷尔蒙和母体效应是否或如何影响这种变异知之甚少。更重要的是，虽然大多数研究都假设健康的结果是基于海马体的变化，但还没有对这一假设进行测试。这项研究的主要目标是观察雄性侧斑蜥蜴(Uta Stansburiana)海马区体积、神经元数量和神经发生的遗传、母体、激素和经验基础，以及海马区变异的健康后果。因此，这项研究有5个主要目标：(1)确定海马区的变化是否是遗传编码的，并与特定的遗传组合有关；(2)探索母体效应，如雌二醇在蛋黄中沉积的形式，是否会导致海马区的变异；(3)操纵男性的睾丸素，以确定性腺激素的差异是否介导了海马体形态的潜在变化；(4)探索空间使用经验是否可以诱导或增强海马区的变化；以及(5)评估自然和损伤诱导的海马区属性的变化是否与健康，即生存有关。因此，这项研究将海马体变异的机制、发育和健康后果联系起来。这项研究将为未被充分代表的本科生提供跨学科的研究培训，并通过K-12科学视频游戏、流行印刷、视觉媒体和社区大学的演示来教育普通公众。

Spatial memory use has been associated with many behaviors such as territoriality, mate choice, navigation and acquisition of food resources. Differential demands on spatial abilities have been shown to affect the hippocampus, the region of the brain thought partially responsible for spatial processing. Although many studies have found a positive association between space use strategies and hippocampal structure, little is known about the causes of variation in the hippocampus and if or how genetics, experience, hormonal and maternal effects influence this variation. More importantly, while most studies assume fitness consequences based on hippocampal variation, there have been no tests of this assumption. The primary goal of this research is to look at the genetic, maternal, hormonal, and experiential basis of variation in the volume, number of neurons and neurogenesis in the hippocampus, as well as the fitness consequences of variation in the hippocampus of male side-blotched lizards (Uta stansburiana). Consequently, this study has 5 primary goals: (1) to determine whether changes in the hippocampus are genetically encoded and relate to particular genetic combinations, (2) to explore if maternal effects, in the form of estradiol deposition in egg yolk, can cause variation in the hippocampus, (3) to manipulate testosterone in males to gauge if differences in gonadal hormones mediate underlying changes in hippocampal morphology, (4) to explore if changes in the hippocampus can be induced or enhanced by spatial use experiences, and (5) to assess if natural and lesion-induced variation in hippocampal attributes relate to fitness, namely survival. Thus, this research links the mechanism, developmental and fitness consequences of variation in the hippocampus. This study will provide interdisciplinary research training to underrepresented undergraduate students, as well as educating the general public via K-12 scientific videogames, popular print, visual media and presentations at community colleges.