Genetic analysis for learning and instinctive behaviors by gene targeting mice.

哺乳动物的神经系统构成了一个巨大的神经网络，并调节各种行为，如运动，感觉，识别，情感，记忆和学习。问题是这些神经网络在发育过程中是如何系统地形成的，以及它们如何调节行为。Fyn是Src家族激酶的成员，一种非受体型酪氨酸激酶，其缺陷导致小鼠空间学习障碍。在本研究项目中，我们首先证实了Fyn基因的破坏会导致其他几种行为异常。他们有吸吮问题和更高的恐惧反应分数在新奇偏好和被动回避测试，表现出更强的光厌恶在明暗选择测试，并对恐惧诱导的环境和听觉引发的听源性癫痫发作反应过度。在突变体中还观察到海马结构的神经细胞层和嗅球的肾小球的解剖缺陷。因此，t ...更多信息 Fyn信号通路将为哺乳动物神经系统的形态学、电生理学和行为学研究提供新的视角。其次，我们集中在脑形成和几个行为形成的Fyn的分子功能。我们研究了对各种惊厥药物引起的癫痫发作的敏感性，这些药物包括戊四氮、印防己毒素、荷包牡丹碱、红藻氨酸、N-甲基-D-天冬氨酸（NMDA）和士的宁。当给予戊四氮、印防己毒素、荷包牡丹碱、红藻氨酸或NMDA时，Fyn缺陷小鼠明显更容易出现肌阵挛性惊厥。另一方面，当给予士的宁时，Fyn缺陷小鼠的癫痫发作易感性没有发现差异。这些结果为Fyn缺陷小鼠对抗GABA能药物和中枢兴奋性氨基酸激动剂诱导的癫痫发作的异常易感性提供了证据。利用酵母双杂交系统从新生小鼠脑中分离到5个与Fyn直接相关的cDNA克隆。序列分析表明，其中三个是以前报道的分子，SON，tctex-1和hnRNP K，两个克隆编码新的序列。据报道，hnRNP K与Fyn相关。获得了新克隆82的全长cDNA，其推导的氨基酸序列与RNA结合蛋白同源。许多Fyn结合分子的分离表明，在小鼠大脑中，Fyn通过与多个分子结合来介导多个信号通路，并且其中一些通路在决定某种类型的行为中起关键作用。第三，我们新生产了NMDA受体亚型的基因敲除小鼠; ε 1，ε 2，ε 4，谷氨酸受体; δ 2和GAD 65。这些基因缺陷小鼠分别表现为空间学习能力下降、吮吸行为缺陷、自发活动减少、突触畸形和对药物敏感性不同。我们认为要在更少的

The mammalian nervous system constitutes an enormous neural network and regulates various behaviors such as locomotion, sense, recognition, emotion, memory and learning. The question is how these neural networks are systematically formed during development and how they regulate behaviors. Fyn is a member of the Src family kinases, a non-receptor-type tyrosine kinase and its deficiencies causes impairments of spatial learning in mice. In this reserch project, firstly we have confirmed that gene disruption of Fyn causes several other behavioral abnormalities. They have suckling problem and higher fear-response scores in the novelty preferance and passive avoidance tests, exhibit stronger light aversion in the light-dark choice test, and are hyperresponsive to fear-inducing environments and to acoustically primed audiogenic seizures. Anatomical defects in the neural cell layr of the hippocampal formation and in the glomeruli of the olfactory bulb were also observed in the mutants. Thus, t … More he Fyn signaling pathway should offer insights into the morphological, electrophysiological, and behavioral events in the mammalian nervous system. Second we focused to molecular function of Fyn during brain formation and on several behavior formation. We examined the susceptibility to seizures induced by various convulsive drugs, including, pentylenetetrazol, picrotoxin, bicuculline, kainic acid, N-methyl-D-aspartate (NMDA) and strychine. Fyn-deficient mice were significantly more likely to show myoclonic convulsions, when pentylenetetrazol, picrotoxin, bicuculline, kainic acid, or NMDA were administered. On the other hand, no difference in seizure susceptibility was found in Fyn-deficient mice, when strychinine was administered. These results provide evidence of abnormal susceptibility to seizures induced by anti-GABAergic agents and agonists for central excitatory amino acids in Fyn-deficient mice. And we isolated five cDNA clones that directly associate with Fyn in neonatal mouse brain by using a two hybrid yeast system. Sequence analyzes revealed that three of them are previously reported molecules, SON,tctex-1 and hnRNP K,and two clones encode novel sequences. The hnRNP K has been reported to asssociate with Fyn. A full-length cDNA of novel clone 82 was obtained and its deduced amino acid sequence was homologous to the RNA-binding proteins. Isolation of many Fyn-binding molecules suggest that, in the mouse brain, Fyn mediates multiple signaling patheways by binding to multiple molecules and that some of these pathways play critical roles in determing a certain type of behavior. Third we newly producted gene-knocked out mice for NMDA receptor subtypes ; epsilon1, epsilon2, epsilon4, glutamate receptor ; delta2, and GAD65. These gene-dificient mice have impaired of spatial learning, defects of suckling behavior, reduced spontaneous activity, malformation of synapse and different susceptibility to seizure-induced drug, respectivelity. We think to be successful in Less