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育障碍，被假设为包括 神经元能功能、异常N-甲基-D-天冬氨酸受体（NMDAR）信号传导和改变 内侧前额叶皮层（mPFC）的兴奋/抑制（E/I）平衡。一个关键的障碍， 改善精神分裂症的治疗和预防策略是对精神分裂症的作用缺乏了解。 突触前谷氨酸通过内源性皮层囊泡释放到GABA能中间神经元 转运蛋白-2（VGLUT 2）突触在调节E/I平衡中的作用，以及这可能如何影响PV-2的成熟。 含有中间神经元。我们的目标是改善精神分裂症的治疗和预防策略， 开发和提供VGLUT 2介导的谷氨酸释放的作用和影响的理解 PV抑制系统的功能障碍我们的中心假设是VGLUT 2提供谷氨酸 mPFC中的新皮质PV+抑制性中间神经元，这对 兴奋/抑制（E/I）平衡和工作记忆。我们的目标是：（1）建立功能性 VGLUT 2突触在体内和体外靶向mPFC中的PV+神经元间系统，（2）证明了VGLUT 2突触在体内和体外靶向mPFC中的PV+神经元间系统。 VGLUT 2突触的缺失减少了E-I突触处的谷氨酸释放，并抑制了抑制性谷氨酸释放。 （3）显示条件性VGLUT 2敲除（KO）小鼠显示工作记忆缺陷。 我们的预期结果将是：（1）理解内在皮层VGLUT 2突触与 E/I平衡，因为它们靶向复发性抑制性反馈神经元，并表现出活性依赖性的 （2）条件性VGLUT 2基因敲除小鼠皮质VGLUT 2表达缺失 导致PV+中间神经元中GAD 67的减少，并抑制抑制突触传递到 锥体神经元，（3）确认皮质边缘回路中VGLUT 2编码的传递对于 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， 结果将提供的是一个重要的一步，治疗洞察认知障碍相关的 并了解VGLUT 2介导的释放对精神分裂症的作用和影响。 PV-神经元间系统的成熟和E/I平衡。目的1将检验内在皮质 VGLUT 2突触与E/I平衡相关，因为a）它们靶向PV+ GABA能中间神经元，B）它们 表现出谷氨酸的活性依赖性释放，和c）它们的丧失抑制了突触传递， MPFC。我们将利用在PV+中间神经元中选择性表达EGFP的GAD 67 gfp+转基因小鼠， 免疫荧光和电生理学研究。目标2将检验VGLUT 2编码的 发育过程中皮质边缘回路的兴奋性传递对成人的工作记忆至关重要， 在T-迷宫中使用两行连续延迟交替任务评估工作记忆功能， VGLUT 2失活发生在发育早期的小鼠和青春期小鼠中。