The effect of brain derived neurotrophic factor on presynaptic function

脑源性神经营养因子对突触前功能的影响

• 批准号: 10685272
• 负责人: Camille Wang
• 金额: $ 3.91万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-01 至 2024-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10685272
• 关键词: Action Potentials; Acute; Affect; Affinity; Antidepressive Agents; Bathing; Binding; Biological; Biology; Brain; Brain-Derived Neurotrophic Factor; Calcium; Calcium Signaling; Cell Culture Techniques; Central Nervous System; Characteristics; Chronic; Clinical; Communication; Critical Thinking; Data; Development; Disease; Dissociation; Down-Regulation; Drug Targeting; Egtazic Acid; Environment; Event; Excitatory Synapse; Fluorescent Probes; Functional disorder; Glutamates; Goals; Growth Factor; Hippocampus; Imaging Techniques; In Vitro; Individual; K 252a; Ketamine; Knockout Mice; Left; Link; Long-Term Potentiation; Major Depressive Disorder; Measures; Mental Depression; Mental disorders; Molecular; Mus; Neurons; Noise; Optics; Pathway interactions; Phosphotransferases; Physiological; Physiology; Play; Presynaptic Terminals; Prevention; Probability; Property; Proteins; Psychiatry; Publishing; Regulation; Research; Role; Schizophrenia; Selective Serotonin Reuptake Inhibitor; Signal Pathway; Signal Transduction; Slice; Source; Stress; Synapses; Synaptic Transmission; Synaptic Vesicles; Synaptic plasticity; System; Technical Expertise; Techniques; Technology; Testing; Therapeutic; Training; Transfection; Treatment Factor; Tropomyosin; Vesicle; Viral; Visualization; Work; antidepressant effect; chelation; collaborative environment; conditional knockout; genetic approach; genetic manipulation; improved; inhibitor; insight; neural circuit; neuropsychiatric disorder; neuropsychiatry; neurotransmission; neurotransmitter release; neurotrophic factor; novel; novel therapeutics; optical imaging; pharmacologic; postsynaptic; presynaptic; receptor; response; skills; spatiotemporal; supportive environment; synaptic function; tool; trafficking

PROJECT SUMMARY Brain derived neurotrophic factor (BDNF) is a prevalent neurotrophin that modulates synaptic physiology and plasticity in the central nervous system. Multiple lines of evidence point towards its involvement in mental health disorders such as depression and schizophrenia, as well as the biological basis for an antidepressant effect. Yet despite its demonstrated involvement in neuropsychiatric diseases, very few studies have investigated how BDNF affects the presynaptic terminal, despite it being a fundamental component of neurotransmission. This is in part due to the difficulty of studying the presynapse and the lack of available technology to do so until more recently. Previously published work using viral manipulation in hippocampal slices demonstrates that BDNF acts upon the high affinity TrkB receptor at the presynapse to increase release probability, or the likelihood that a vesicle will be release in response to an action potential. With the resulting hypothesis that BDNF signaling specifically targets presynaptic function via TrkB signaling pathways, this proposal aims to investigate the molecular basis of BDNF’s effect at the presynapse. This will be done through the following: first, examining the effect of BDNF on excitatory neurotransmission (subaim 1.1). Preliminary data from subaim 1.1 show that in dissociated hippocampal cultures, release probability at excitatory synapses is increased in response to acute BDNF treatment in a manner dependent on TrkB activation. Subaim 1.2 will dissect the potential mechanisms underlying this effect through using pharmacological approaches to screen for potential downstream pathways that are involved in this effect. Because the spatiotemporal context of BDNF activity is critical in its effect, I will also use cTrkB KO hippocampal cultures to examine the spontaneous and evoked release events as a result of endogenous BDNF manipulation (subaim 1.3). Local calcium transients at synapses are strongly linked to neurotransmitter release, especially evoked release. I will thus investigate how presynaptic calcium transients are affected by exogenous BDNF (subaim 2.1), endogenous BDNF using cTrkB cultures (subaim 2.2), and whether BDNF utilizes calcium to modulate neurotransmission (subaim 2.3). The proposed studies will involve optical imaging of in vitro neuron cultures transfected or infected with fluorescent probes to study the presynase, as well as pharmacological and genetic manipulation tools to provide further mechanistic insight into findings. This research will further current understanding of the fundamental role of BDNF at the synapse, with implications for improving current therapeutics such as for antidepressants. The proposed research will be accomplished through a thoughtfully developed training plan that involves opportunities to further critical thinking skills, technical expertise, and scientific communication. Additionally, the research environment provided by the MSTP, Vanderbilt Brain Institute, and Department of Psychiatry is ideal for the proposed research and training plan, a collaborative and supportive environment, and focus on trainee development.

项目总结 脑源性神经营养因子(BDNF)是一种广泛存在的调节突触生理的神经营养因子 以及中枢神经系统的可塑性。多条证据表明它与精神疾病有关 抑郁症和精神分裂症等健康障碍，以及抗抑郁药物的生物学基础 效果。然而，尽管它被证明与神经精神疾病有关，但很少有研究调查 脑源性神经营养因子如何影响突触前终末，尽管它是神经传递的基本组成部分。 这在一定程度上是由于研究突触前的困难和缺乏可用的技术，直到 就在最近。之前发表的在海马片上进行病毒操作的研究表明，BDNF 作用于突触前的高亲和力TrkB受体，以增加释放概率，或 囊泡将被释放，以响应动作电位。由此产生的假设是脑源性神经营养因子信号 通过TrkB信号通路特别针对突触前功能，这项提议旨在研究 BDNF在突触前的作用的分子基础。这将通过以下方式完成：首先，研究 脑源性神经营养因子对兴奋性神经传递的影响(子目标1.1)。来自SubAim 1.1的初步数据显示， 分离的海马区培养，兴奋性突触的释放几率增加 BDNF的处理方式依赖于TrkB的激活。Subaim 1.2将剖析潜在的机制 通过使用药理学方法筛选潜在的下游途径来实现这种效果 与这一效应有关的人。由于BDNF活动的时空背景对其影响至关重要，我将 也使用cTrkB KO海马区培养来检测作为结果的自发和诱发的释放事件 内源性脑源性神经营养因子操作(子目标1.3)。突触的局部钙瞬变与 神经递质的释放，尤其是诱发的释放。因此，我将研究突触前钙离子是如何 受外源BDNF(次级目标2.1)、使用cTrkB培养的内源性BDNF(次级目标2.2)的影响 脑源性神经营养因子是否利用钙调节神经传递(子目标2.3)。拟议的研究将包括 用荧光探针对体外培养的神经元进行光学成像以研究前合成酶， 以及药理学和基因操作工具，以提供对发现的进一步机械性洞察。 这项研究将加深对BDNF在突触中的基础作用的理解，并具有重要意义 用于改善目前的治疗方法，如抗抑郁药。拟议的研究将完成。 通过深思熟虑制定的培训计划，包括进一步提高批判性思维技能的机会， 技术专长和科学交流。此外，MSTP提供的研究环境， 范德比尔特脑研究所和精神病学系是拟议的研究和培训计划的理想选择，a 协作和支持的环境，并专注于学员的发展。