Hormones, Experience and Hippocampal Neurogenesis

描述（由申请人提供）：本提案的广泛、长期目标是更好地了解海马中成人神经发生的功能。以下方法将用于实现这一总体目标：1）检查社会和空间复杂体验对新神经元、激素水平和学习的影响; 2）探索睡眠、新神经元和学习之间的相互作用; 3）确定新神经元耗竭对海马功能的影响; 4）表征成熟和未成熟神经元之间的差异。生活在标准实验室条件下对海马体中新神经元的存活有着深远的负面影响。因此，提出的实验的一个主要目标是确定一个自然的，相对复杂的环境，是重要的海马神经发生的元素。海马中新细胞的产生、存活和表型将通过溴脱氧尿苷（BrdU）标记结合细胞类型特异性标记物的免疫细胞化学来评估，激素水平将通过放射免疫测定来评估，海马功能将通过各种关联学习任务来评估，包括跟踪眨眼条件反射、跟踪恐惧条件反射、背景恐惧条件反射和Morris水迷宫中的空间学习。这些技术将应用于那些经历过不同社会经历、被剥夺了不同睡眠阶段或新神经元被耗尽的动物。最后一系列研究将检查成年期产生的神经元与发育期间产生的神经元的结构和生化特征。这些实验将使用神经解剖束示踪结合BrdU标记，电子显微镜结合3 H-胸苷标记和共聚焦显微镜。由于压力、睡眠和海马体与多种精神疾病有关，其中许多都与认知有关，因此这些结果可能会阐明精神病理学发展的大脑机制。

DESCRIPTION (provided by applicant): The broad, long-term objective of this proposal is to gain a better understanding of the function of adult neurogenesis in the hippocampus. The following approaches will be used to achieve this general goal: 1) examination of the impact of socially and spatially complex experiences on new neurons, hormones levels and learning; 2) Exploration of the interaction between sleep, new neurons and learning; 3) determination of the impact of new neuron depletion on hippocampal function; and 4) characterization of differences between mature and immature neurons. Living under standard laboratory conditions has a profound negative impact on the survival of new neurons in the hippocampus. Therefore, a major goal of the experiments proposed is to identify the elements of a naturalistic, relatively complex environment that are important for hippocampal neurogenesis. The production, survival and phenotype of new cells in the hippocampus will be assessed with bromodeoxyuridine (BrdU) labeling combined with immunocytochemistry for cell-type specific markers, hormone levels will be assessed via radioimmunoassay and hippocampal function will be assessed by a variety of associative learning tasks, including trace eyeblink conditioning, trace fear conditioning, context fear conditioning and spatial learning in a Morris water maze. These techniques will be applied to animals that have been exposed to different social experiences, deprived of different stages of sleep or pharmacologically depleted of new neurons. A final series of studies will examine the structural and biochemical characteristics of neurons generated in adulthood compared to those generated during development. These experiments will use neuroanatomical tract tracing combined with BrdU labeling, electron microscopy combined with 3H-thymidine labeling and confocal microscopy. Because stress, sleep and the hippocampus have been linked to several psychiatric conditions, many of which have a cognitive component, these results may elucidate the brain mechanisms that underlie the development of psychopathology.