MOLECULAR CORRELATES OF ADULT SYNAPTOGENESIS

描述（来自申请人的摘要的逐字）：海马是一个神经元。 重要的认知大脑区域，由于其在学习和 记忆在成年雌性大鼠海马中，CA 3-CA 1突触 经历突触发生和突触脱落的阶段性周期，每4或5个 日发情周期虽然这个周期需要卵巢类固醇雌激素， CA 1和CA 3中的兴奋性锥体神经元缺乏常规的基因组 雌激素受体（ER α）。这一非凡的观察导致了许多， 关于卵巢激素依赖性周期控制的未回答的问题 海马体中的成年突触发生。这也让我们不禁要问， 同样的循环也发生在大脑皮层。 采用PCR、北方和南方杂交等分子生物学技术， 和差异显示，我们将发现一组分子， 在海马CA 1中以雌二醇依赖性方式选择性合成， CA 3.选择性合成的时间过程将使我们能够定义一个时间的 从早期时间点表达序列的级联，这些推测 控制转录因子，通过后来的，可能包括 参与突触组装的序列。通过屏蔽 与NMDA受体拮抗剂的雌二醇依赖性突触形成，和 独立地，通过破坏已经形成的突触，我们将识别 一个特别有趣的子集这些表达的转录本。这 选择性亚组将包括特异性针对所述细胞的雌二醇依赖性转录物。 突触级联反应 解释雌二醇依赖的转录本所起的作用将是 通过电生理相关性、解剖定位和 与已知分子的结构相似利用自然循环的雌性 以及接受雌二醇替代的卵巢切除动物，我们将 电生理学评估CA 1中的NMDA受体功能，并将其与 改变了基因表达原位杂交，必要时补充 通过显微切割，将允许这些新基因的细胞定位 锥体和/或非锥体神经元和/或神经胶质的产物。原位 随后将使用杂交1）搜索相似表达 大脑皮层和下丘脑的模式，和2）比较这种形式的 成年大鼠与发育不成熟的雄性大鼠的突触发生。 最后，我们开始一系列的实验，包括克隆和绘制 小鼠和人类染色体的新发现基因。这些研究将 最终在测试这些新的基因产物的功能， 转基因老鼠

DESCRIPTION (Verbatim from the Applicant's Abstract): The hippocampus is an important cognitive brain region by virtue of its critical role in learning and memory. In the adult hippocampus of the female rat, the CA3-CA1 synapses undergo phasic cycles of syanptogenesis and synapse shedding with each 4 or 5 day estrous cycle. Although this cycle requires the ovarian steroid estrogen, the excitatory pyramidal neurons in CA1 and CA3 lack the conventional, genomic estrogen receptor (ER alpha). This remarkable observation leads to many, unanswered questions about the control of ovarian steroid-dependent cycle of adult synaptogenesis in the hippocampus. It also begs us to ask whether this same cycle also occurs in cerebral cortex. Using the molecular biological techniques of PCR, Northern and Southern blots, and differential display, we will uncover a set of molecules that are selectively synthesized in an estradiol-dependent manner in hippocampal CA1 and CA3. The time course of selective synthesis will enable us to define a temporal cascade of expressed sequences from early time points, those presumably controlling transcription factors, through later ones, possibly including sequences involved in synapse assembly. By pharmacologically blocking estradiol-dependent synapse formation with an NMDA receptor antagonist, and independently, by hormonally undoing synapses already formed, we will identify a particularly interesting subset of these expressed transcripts. This selective subset will include estradiol-dependent transcripts specific to the synaptogenetic cascade. Interpreting the roles played by the estradiol-dependent transcripts will be facilitated by electrophysiological correlations, anatomical localization, and by structural similarities to known molecules. Using naturally cycling females and ovariectomized animals receiving estradiol replacement, we will electrophysiologically assess NMDA receptor function in CA1 and correlate this with altered gene expression. In situ hybridization, supplemented as necessary with microdissection, will permit the cellular localization of these novel gene products to pyramidal and/or nonpyramidal neurons and/or glia. In situ hybridization will subsequently be used 1) to search for similar expression patterns in cerebral cortex and hypothalamus, and 2) to compare this form of adult synaptogenesis with that in the developmentally immature, male rat. Finally, we begin a series of experiments, including cloning and mapping the newly discovered genes to mouse and human chromosomes. These studies will eventually culminate in testing the function of these novel gene products in the genetically altered mouse.