The Relationship Between Reliance on Food Caching, Spatial Memory and the Hippocampus - An Intraspecific Comparison

对食物缓存的依赖、空间记忆和海马体之间的关系——种内比较

• 批准号: 0615021
• 负责人: Vladimir Pravosudov
• 金额: --
• 依托单位: Board of Regents, NSHE, obo University of Nevada, Reno
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-09-01 至 2011-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0615021&HistoricalAwards=false
• 关键词: Relationship; Between; Reliance; Food; Caching

Food-storing birds rely on their food caches to survive winters and use spatial memory for successful food recovery. Both theoretical and empirical studies suggest that energetically demanding ecological conditions should result in more intensive food caching. Thus, environmental conditions that place higher demands on spatial memory and the hippocampus result in enhanced spatial memory and an enlarged hippocampus with more neurons will be investigated. A comparative method and a common garden experiment will be used to test a prediction that black-capped chickadees in northern populations have evolved enhanced spatial memory and an enlarged hippocampus with more neurons. First, hippocampal structure in black-capped chickadees from twelve populations along a latitudinal gradient will be compared. Theoretical models also suggest that more caching along with successful cache recovery should significantly increase the probability of survival in birds specifically when environmental conditions are more energetically demanding and unpredictable like those in northern locations. Therefore chickadees living in more northern environments should depend on caches more heavily because of harsher winter conditions, and thus should experience higher demands for spatial memory than their more southern conspecifics. To determine whether differences in memory and the hippocampus between northern and southern chickadees have evolved, a common garden experiment in which northern and southern black-capped chickadees taken from nests and hand-raised under identical laboratory conditions will be conducted to test two predictions from the adaptive specialization hypothesis: (1) individuals in northern populations should have a relatively larger hippocampus with more neurons and higher cell proliferation rates; and (2) these differences between northern and southern populations have evolved as a result of greater selection pressure on memory and the hippocampus and thus they have a genetic basis. Studying the relationship between environment, memory and the hippocampus in birds will advance our understanding of the evolution of memory and the brain. The proposed activity will provide interdisciplinary research training to one postdoctoral associate, to 2-3 undergraduate students and to 1-2 interns from a community college per year. Every effort will be made to recruit candidates for these positions from underrepresented groups in the biological sciences. The results of the study will be presented at national and international meetings, and published in peer-reviewed journals. Results and rationale of the proposed study will made available to a broader audience through a freely accessible web site, publications in popular media, presentations at local community colleges and through teaching undergraduate classes. All processed brain tissue will be used in teaching undergraduate and graduate students. The proposed study is interdisciplinary and it will bolster integration between the fields of behavioral ecology, neurobiology, and endocrinology.

储存食物的鸟类依靠它们储存的食物来过冬，并利用空间记忆来成功回收食物。 理论和实证研究都表明，高强度的生态条件应该导致更密集的食物储存。 因此，对空间记忆和海马体提出更高要求的环境条件会导致空间记忆增强和海马体增大并具有更多神经元，我们将对此进行研究。 将使用比较方法和常见的花园实验来检验北方种群的黑冠山雀已经进化出增强的空间记忆和具有更多神经元的扩大的海马体的预测。 首先，将比较沿纬度梯度十二个种群的黑冠山雀的海马结构。 理论模型还表明，更多的缓存以及成功的缓存恢复应该会显着增加鸟类的生存概率，特别是当环境条件对能量要求更高且不可预测时，例如北方地区。 因此，由于冬季条件更加严酷，生活在北方环境中的山雀应该更加依赖缓存，因此与南方的同种相比，它们对空间记忆的需求也更高。 为了确定北方和南方山雀之间的记忆和海马体是否存在进化差异，我们将进行一项常见的花园实验，在该实验中，将北方和南方黑顶山雀从巢中取出并在相同的实验室条件下进行手工饲养，以检验来自北方和南方山雀的两个预测。适应性特化假说：（1）北方人群的海马体应相对较大，神经元较多，细胞增殖率较高； （2）北方和南方人群之间的这些差异是由于记忆和海马体承受更大的选择压力而进化的，因此它们具有遗传基础。 研究环境、记忆和鸟类海马体之间的关系将增进我们对记忆和大脑进化的理解。 拟议的活动每年将为社区学院的一名博士后、2-3 名本科生和 1-2 名实习生提供跨学科研究培训。我们将尽一切努力从生物科学领域代表性不足的群体中招募这些职位的候选人。 研究结果将在国内和国际会议上公布，并在同行评审期刊上发表。拟议研究的结果和基本原理将通过可免费访问的网站、流行媒体上的出版物、在当地社区大学的演讲以及本科生课程的教学，向更广泛的受众提供。所有处理过的脑组织将用于本科生和研究生的教学。拟议的研究是跨学科的，它将促进行为生态学、神经生物学和内分泌学领域之间的整合。