Effect of social environment on memory, hippocampal structure and neurogenesis

描述（由申请人提供）：环境条件可能对维持心理健康至关重要，包括记忆及其神经机制。尽管人们对丰富的物理环境对记忆和海马体的影响给予了很大的关注，但社会环境的影响仍然很少。包括人类在内的许多动物物种都是高度社会化的，复杂的社会互动是其自然环境的组成部分。为了了解健康记忆的维持和社交障碍的神经后果，研究社会环境如何影响记忆和大脑至关重要。本研究将以山雀为模型，探讨社会环境、记忆、海马结构和神经发生之间的关系。海马与记忆功能有关，它的可塑性众所周知，越来越多的证据表明，在整个成年期，海马中会产生新的神经元。这项拟议的研究将专门研究自然丰富的社会环境是否需要维持健康的记忆和大脑，以及社会隔离是否会导致记忆受损，海马神经元减少和神经发生率降低，包括细胞增殖和神经元存活。成年的同龄鸟将被随机分配到五个不同的社会环境中：孤独，中性雄性对，中性雌性对，雄性-雌性对和包括两个雄性-雌性对的群体。成年人和山雀自然存在于由雌雄配对组成的大群体中-因此最后一个实验组将代表最自然的社会环境。将所有鸡饲养在笼中，为所有组的每只鸡提供相等的空间。所有鸟类将在其指定的社会环境中保持90天，在此期间，它们将定期接受各种记忆任务的测试。在实验结束时，将所有的鸟处死以分析海马结构（体积、神经元计数）和神经发生（使用BrdU和磷酸化组蛋白H3有丝分裂标记物）。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了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.