VGLUT2 Transmission in Prefrontal Cortex and Working Memory

前额皮质和工作记忆中的 VGLUT2 传输

• 批准号: 8700767
• 负责人: JEFFREY D ERICKSON
• 金额: $ 21.89万
• 依托单位: LSU HEALTH SCIENCES CENTER
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-05-01 至 2016-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8700767
• 关键词: Adolescent; Adult; Attention; Behavioral; Development; Disinhibition; Equilibrium; Exhibits; Feedback; Frequencies; Functional disorder; Glutamates; Goals; Hippocampus (Brain); Immunofluorescence Immunologic; Impaired cognition; In Vitro; Interneurons; Knockout Mice; Knowledge; Lead; Learning; Measures; Medial; Mediating; Memory; Memory impairment; Mus; N-Methylaspartate; Neurons; Outcome; Parvalbumins; Patients; Physiological; Prefrontal Cortex; Prevention; Primates; Receptor Signaling; Recurrence; Reversal Learning; Rodent; Role; Schizophrenia; Short-Term Memory; Slice; Synapses; Synaptic Transmission; System; Testing; Therapeutic; Transgenic Mice; aspartate receptor; base; developmental disease; endophenotype; gamma-Aminobutyric Acid; hippocampal pyramidal neuron; improved; in vivo; insight; neocortical; postsynaptic; presynaptic; prevent; public health relevance; selective expression; transmission process; treatment strategy; vesicular glutamate transporter 2

Abstract. Schizophrenia is a developmental disorder that is hypothesized to include alterations in glutamatergic function, aberrant N-methyl-D-aspartic acid receptor (NMDAR) signaling and altered excitatory/inhibitory (E/I) balance in the medial prefrontal cortex (mPFC). A critical barrier to progress in improving strategies for the treatment and prevention of schizophrenia is a lack of understanding of the role of presynaptic glutamate release onto GABAergic interneurons by intrinsic cortical vesicular glutamate transporter-2 (VGLUT2) synapses in regulating E/I balance and how this may impact the maturation of PV- containing interneurons. Our goal is to improve strategies for the treatment and prevention of schizophrenia by developing and providing an understanding of the role and influence of VGLUT2-mediated glutamate release on the dysfunction of the PV-inhibitory system. Our central hypothesis is that VGLUT2 provides glutamate to neocortical PV+ inhibitory interneurons in the mPFC that is important for the maturation of excitatory/inhibitory (E/I) balance and to working memory. Our objectives are to (1) establish that functional VGLUT2 synapses target the PV+ interneuronal system in mPFC in vivo and in vitro, (2) demonstrate that the loss of VGLUT2 synapses decreases glutamate release at E-I synapses and suppresses inhibitory transmission, and (3) show that conditional VGLUT2 knockout (KO) mice display deficits in working memory. Our expected outcomes will be (1) an understanding that intrinsic cortical VGLUT2 synapses are relevant to E/I balance because they target recurrent inhibitory feedback neurons and exhibit activity-dependent release of glutamate, (2) the knowledge that loss of intrinsic cortical VGLUT2 expression in conditional VGLUT2 KO mice leads to a reduction in GAD67 in PV+ interneurons and suppresses inhibitory synaptic transmission onto pyramidal neurons, and (3) to affirm that VGLUT2-encoded transmission in corticolimbic circuits is critical to working memory. The impact of these results on strategies for treating and preventing schizophrenia that our outcomes will provide is an important step towards therapeutic insight into the cognitive impairment associated with schizophrenia and an understanding of the role and influence of VGLUT2-mediated release on the maturation of the PV-interneuronal system and E/I balance. Aim 1 will test the hypothesis that intrinsic cortical VGLUT2 synapses are relevant to E/I balance because a) they target PV+ GABAergic interneurons, b) they exhibit activity-dependent release of glutamate, and c) their loss suppresses inhibitory synaptic transmission in the mPFC. We will utilize GAD67gfp+ transgenic mice that selectively express EGFP in PV+ interneurons for immunofluorescence and electrophysiologic studies. Aim 2 will test the hypothesis that VGLUT2-encoded excitatory transmission in corticolimbic circuits during development is critical to working memory in adults, by assessing working memory function using the continuous delayed alternation task in a T-maze in two lines of mice where VGLUT2 inactivation occurs early in development and in adolescent mice.

抽象的。精神分裂症是一种发展障碍，假设包括改变 谷氨酸能函数，异常N-甲基-D-天冬氨酸受体（NMDAR）信号传导 内侧前额叶皮层（MPFC）中的兴奋性/抑制（E/I）平衡。进步的关键障碍 改善治疗和预防精神分裂症的策略是缺乏了解的作用 内在皮质囊泡谷氨酸到GABA能中间神经元的突触前谷氨酸释放 转运蛋白2（VGLUT2）在调节E/I平衡方面的突触以及这可能会影响PV-的成熟 包含中间神经元。我们的目标是通过通过 发展并提供对VGLUT2介导的谷氨酸释放的作用和影响的理解 在PV抑制系统的功能障碍上。我们的中心假设是VGLUT2提供谷氨酸 对于MPFC中的新皮质PV+抑制性中间神经元，这对于成熟很重要 兴奋/抑制（E/I）平衡和工作记忆。我们的目标是（1）确定该功能 VGLUT2突触针对MPFC的PV+体内和体外中的PV+中间系统，（2）证明了该系统 vglut2突触的损失可在E-I突触下降低谷氨酸释放并抑制抑制作用 传输，（3）显示有条件的VGLUT2敲除（KO）小鼠在工作记忆中显示缺陷。 我们的预期结果将是（1）理解，内在的皮质VGLUT2突触与 e/i平衡是因为它们靶向复发性抑制反馈神经元，并表现出活动依赖性释放 谷氨酸，（2）有条件vglut2 ko小鼠中内在皮质vglut2表达的丧失的知识 导致PV+中间神经元中的GAD67降低，并抑制抑制性突触传播 锥体神经元和（3）确认Corticolimbic电路中VGLUT2编码的传播对 工作记忆。这些结果对治疗和预防精神分裂症的策略的影响 结果将提供是迈向治疗洞察力的重要一步 有精神分裂症以及对VGLUT2介导的释放对该的作用和影响的理解 PV interneronal系统和E/I平衡的成熟。 AIM 1将测试内在皮质的假设 VGLUT2突触与E/I平衡有关，因为A）它们针对PV+ GABA能中间神经元，b）它们 表现出活性依赖性谷氨酸的释放，c）它们的损失抑制了抑制性突触传播 MPFC。我们将利用GAD67GFP+转基因小鼠，在PV+ INTERRONS中有选择地表达EGFP 免疫荧光和电生理研究。 AIM 2将测试vglut2编码的假设 开发过程中皮质降虫电路中的兴奋性传播对于成年人的工作记忆至关重要， 使用连续延迟交替任务在T迷宫中评估工作记忆函数 vglut2失活的小鼠在发育早期和青少年小鼠中发生。