Adolescent ethanol exposure and NMDA receptor maturation in cerebellum

描述（由申请人提供）：乙醇是青少年最常滥用的药物，但我们对其在青少年大脑中的作用知之甚少。我们试图了解乙醇对哺乳动物小脑皮质的活动依赖性成熟和功能的影响，这主要是由兴奋性神经递质谷氨酸介导的。这一点很重要，因为小脑在运动和认知功能中起着关键作用，并且在青少年中继续经历实质性的增长。特别是，N-甲基-D-天冬氨酸受体（NR）的组成和功能发生变化，乙醇是许多脑区和神经元类型（包括小脑）中NR的拮抗剂。因此，预计乙醇会影响NR本身以及位于NR下游的信号级联，特别是胞质溶胶和细胞核中的Ca 2+和钙调蛋白依赖性激酶。我们将使用大鼠模型和分子生物学，免疫化学和解剖技术的组合，专注于核受体和钙调蛋白激酶在内部颗粒层。我们假设，在青春期前开始长期使用乙醇将不可逆转地干扰海马能苔藓纤维颗粒神经元突触电路和信号分子的发育和功能。这将通过NR 2A-C亚基mRNA和免疫反应性蛋白的特异性和持续性改变、NR 1中的外显子选择以及下游Ca 2+依赖性激酶CaMKK和CaMKIV的成熟来反映。我们不能预测乙醇引起的大量细胞损失，因为在出生后4 - 6天给予新生儿乙醇时通常会观察到死亡。相反，乙醇预计会干扰突触的成熟，因此，在青少年小脑的信息处理。我们选择了RO 3机制的支持，因为这个试点项目将作为未来研究的基础，探索乙醇对小脑生理和病理生理的功能后果。这些未来的研究将与我们在上州医学和宾厄姆顿大学的合作者的大量投入一起设计，他们是胎儿和青少年酒精研究领域的专家。在这个国家，青少年至少消耗四分之一的酒精，但我们对酒精对青少年大脑的影响知之甚少。小脑皮质在青春期继续经历显著的生长和突触细化，是乙醇最敏感的靶点之一。我们将使用大鼠模型检验乙醇不可逆地干扰兴奋性神经递质分子及其下游效应物成熟的假设。我们的研究结果将作为未来功能研究的基础。

DESCRIPTION (provided by applicant): Ethanol is the most commonly abused drug in adolescents yet we know very little about its actions in adolescent brain. We seek to understand ethanol effects on the activity-dependent maturation and function of the mammalian cerebellar cortex, which is mediated primarily by the excitatory neurotransmitter glutamate. This is important because the cerebellum has critical roles in motor and cognitive functions, and continues to undergo substantial growth in the adolescent. In particular, N-methyl-D-aspartate receptor (NR) composition and function changes, and ethanol is an antagonist of NRs in many brain regions and neuronal types, including cerebellum. As such, ethanol is predicted to influence NRs themselves as well as signaling cascades that lie downstream of NRs, in particular Ca2+ and calmodulin-dependent kinases in the cytosol and nucleus. We will use a rat model and a combination of molecular biological, immunochemical and anatomical techniques, focusing on NRs and CaMKs in the internal granular layer. We hypothesize that chronic use of ethanol beginning in pre-adolescence will irreversibly interfere with the development and function of the glutamatergic mossy fiber-granule neuron synaptic circuitry and signaling molecules. This will be reflected by specific and persistent alterations in NR2A-C subunit mRNAs and immunoreactive proteins, exon selection in NR1, and maturation of the downstream Ca2+-dependent kinases, CaMKK and CaMKIV. We do not predict substantial cell loss in response to ethanol since death is typically observed when ethanol is administered to neonates at postnatal days 4 -6. Rather, ethanol is expected to interfere with synaptic maturation and therefore, information processing in the adolescent cerebellum. We chose the RO3 mechanism of support because this pilot project will serve as a foundation for future studies exploring the functional consequences of ethanol on cerebellar physiology and pathophysiology. These future studies will be designed with substantial input from our collaborators at Upstate Medical and Binghamton Universities who are established experts in the fields of fetal and adolescent alcohol research. Adolescents consume at least one-fourth of alcohol in this country, yet we understand little about ethanol effects in adolescent brain. The cerebellar cortex, which continues to undergo significant growth and synaptic refinement through adolescence is one of the most sensitive targets of ethanol. We will test the hypothesis that ethanol irreversibly interferes with maturation of excitatory neurotransmitter molecules and their downstream effectors using the rat model. Our results will serve as a basis for future functional studies.