Effect of social environment on memory, hippocampal structure and neurogenesis

描述(由申请人提供)：环境条件可能是维持心理健康的关键，包括记忆及其神经机制。虽然丰富的物理环境对记忆和海马体的影响已经引起了很大的关注，但社会环境的影响仍然没有得到充分的研究。包括人类在内的许多动物物种是高度社会性的，复杂的社会性互动是其自然环境不可或缺的一部分。为了了解健康记忆的维持和社交障碍的神经后果，研究社会环境可能如何影响记忆和大脑是至关重要的。这项拟议的研究将以一种觅食鸟类--山地山雀为模型，研究社会环境、记忆、海马体结构和神经发生之间的关系。海马体参与记忆功能，以其可塑性而闻名，越来越多的证据表明，在成年过程中，海马体中会产生新的神经元。这项拟议的研究将专门调查是否需要自然丰富的社会环境来维持健康的记忆和大脑，以及社会孤立是否会导致记忆受损、海马神经元减少以及神经发生率降低，包括细胞增殖和神经元存活。相同年龄的成年鸟类将被随机分配到五个不同的社会环境中：独居的、雌雄同体的雄鸟对、雌雄异体的雌鸟对和包括两对雄鸟和雌鸟的群体。成年人类和山雀自然地存在于由雄性和雌性配对组成的大群体中--因此，最后一个实验群体将代表最自然的社会环境。所有禽鸟将被饲养在笼子里，为所有组别的禽鸟提供相同的空间。所有的鸟都将在指定的社会环境中生活90天，在此期间，它们将接受各种记忆任务的定期测试。在实验结束时，所有的鸟将被处死以进行海马区结构(体积、神经元计数)和神经发生(使用BrdU和磷酸组蛋白H3有丝分裂标记)的分析。这项研究将提供有关社会环境对记忆和海马体影响的重要信息，这反过来可能有助于更好地理解社会障碍对心理健康和大脑的影响。

DESCRIPTION (provided by applicant): Environmental conditions could be critical for maintaining mental health including memory and its neural mechanisms. Whereas much attention has been devoted to the effects of enriched physical environment on memory and the hippocampus, the effects of social environment remain poorly investigated. Many animal species including humans are highly social and complex social interactions are an integral part of their natural environment. To understand maintenance of healthy memory and neurological consequences of social disorders, it is it crucial to investigate how social environment might influence memory and the brain. The proposed study will investigate the relationship between social environment, memory, hippocampal structure and neurogenesis using a food-caching bird, mountain chickadee, as a model. Hippocampus, which is involved in memory function, is well known for its plasticity and there is growing evidence that new neurons are generated in the hippocampus throughout adult life span. The proposed study will specifically investigate whether naturally rich social environment is required for maintaining healthy memory and the brain and whether social isolation results in impaired memory, fewer hippocampal neurons and reduced neurogenesis rates including both cell proliferation and neuron survival. Fully grown birds of the same age will be randomly assigned to five different social environments: solitary, unisex male pairs, unisex female pairs, male-female pairs and groups including two male-female pairs. Adult humans and chickadees naturally exist in large groups consisting of male-female pairs - thus the last experimental group will represent the most natural social environment. All birds will be maintained in cages providing equal space per bird for all groups. All birds will be maintained in their assigned social environment for 90 days during which they will be regularly tested in various memory tasks. At the end of the experiment all birds will be sacrificed for the analyses of the hippocampus structure (volume, neuron count) and neurogenesis (using BrdU and Phospho-histone H3 Mitosis markers). This study will provide important information on the effects of social environment on memory and the hippocampus which, in turn, might help better understand consequences of social disorders for mental health and the brain.