Development of neuronal subtypes and local circuits in the hippocampus

海马神经元亚型和局部回路的发育

• 批准号: 10298128
• 负责人: Jason C. Wester
• 金额: $ 37.28万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-07-01 至 2026-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10298128
• 关键词: ATAC-seq; Acute; Adolescent; Adult; Architecture; Area; Birth; Brain; Brain region; Cell Differentiation process; Cells; Chromatin; Chromatin Structure; Data; Development; Developmental Delay Disorders; Disease; Electric Stimulation; Electrophysiology (science); Embryo; Epigenetic Process; Epilepsy; Exhibits; Gene Expression; Gene Expression Profiling; Genetic Transcription; Health; Hippocampus (Brain); Human; Impairment; Inhibitory Synapse; Intellectual functioning disability; Interneurons; Knock-out; Knowledge; Learning; Location; Long-Term Potentiation; Maintenance; Maps; Mediating; Membrane; Memory; Modification; Molecular; Molecular Genetics; Molecular Profiling; Morphology; Mus; Mutant Strains Mice; Mutation; Neuronal Differentiation; Neurons; Output; Physiology; Play; Positioning Attribute; Process; Property; Proteins; Pyramidal Cells; Radial; Regulator Genes; Regulatory Pathway; Role; Schizophrenia; Series; Slice; Source; Structure; Synapses; Synaptic plasticity; Techniques; Testing; Time; Tissue-Specific Gene Expression; Transcriptional Regulation; Whole-Cell Recordings; Work; autism spectrum disorder; autistic; autistic behaviour; base; chromatin remodeling; conditional knockout; craniofacial; design; disorder risk; entorhinal cortex; environmental enrichment for laboratory animals; epigenetic regulation; experience; experimental study; human disease; insight; memory consolidation; migration; neocortical; neural circuit; neurodevelopment; neuron development; novel strategies; postnatal development; recruit; relating to nervous system; response; risk variant; single-cell RNA sequencing; tool

PROJECT SUMMARY/ABSTRACT During brain development, neurons must properly differentiate into distinct subtypes to assemble healthy circuits. Thus, disruption of this process can impact neural architecture and wiring, and contribute to disorders such as autism, schizophrenia, and epilepsy. The hippocampus is a brain structure crucial for learning and memory, and its function is compromised in these disorders. Excitatory pyramidal cells in area CA1 provide a major output of hippocampal computations to other brain regions. These cells can be parsed based on their physical position within CA1 as “deep” or “superficial.” Deep and superficial hippocampal pyramidal cells are distinct classes of neurons that exhibit differential molecular signatures, electrophysiological properties, sources of afferent input, and circuit connectivity with local inhibitory interneurons. Determining the mechanisms underlying their differentiation is crucial for understanding hippocampal development and function in both health and disease. Superficial pyramidal cells in CA1 preferentially express the transcriptional regulator Satb2, which controls gene expression by modifying chromatin structure. In humans, mutations of Satb2 cause developmental delay, intellectual disability, epilepsy, and autistic behaviors. Our preliminary data show that knocking out Satb2 during early development in mice disrupts the differentiation of superficial pyramidal cells in CA1. Furthermore, there are non-cell-autonomous changes to the migration and survival of distinct subtypes of interneurons in mutant mice relative to controls. In the present proposal, three specific aims will test the hypothesis that early expression of Satb2 is necessary for hippocampal pyramidal cell differentiation and circuit development in CA1, while later expression is necessary to promote experience- dependent synaptic plasticity. These experiments will use molecular genetic tools in mice to conditionally knock out Satb2 from pyramidal cells during both early and late developmental stages. Aim 1 will use electrophysiology and electrical stimulation to study the strength and plasticity of different sources of afferent input to deep and superficial CA1 pyramidal cells in acute slices. This aim will test the hypothesis that early Satb2 expression is necessary to establish differences in afferent input strength, while later expression is necessary for activity-driven synaptic plasticity of these inputs. Aim 2 will use paired whole-cell recordings between pyramidal cells (deep and superficial) and identified subtypes of interneurons to map circuits and study details of their synaptic physiology. This aim will test the hypothesis that early Satb2 expression is necessary to establish circuit motifs between local inhibitory interneurons and superficial pyramidal cells, while later expression is necessary to recruit new inhibitory synapses in response to environmental enrichment. Aim 3 will use single-cell RNA-seq and ATAC-seq to determine how Satb2 knockout alters gene expression and chromatin accessibility in CA1 at multiple developmental timepoints. This aim will provide molecular insight into how Satb2 controls gene expression in CA1 through development, and how its function may change over time.

项目概要/摘要 在大脑发育过程中，神经元必须正确分化成不同的亚型才能组装健康的细胞 因此，这个过程的破坏会影响神经结构和接线，并导致疾病。 例如自闭症、精神分裂症和癫痫症。海马体是对学习和学习至关重要的大脑结构。 CA1 区的兴奋性锥体细胞提供记忆力，其功能在这些疾病中受到损害。 海马计算到其他大脑区域的主要输出可以根据它们进行解析。 CA1 内的物理位置为“深层”或“浅层”。深层和浅层海马锥体细胞是 不同类别的神经元表现出不同的分子特征、电生理特性、 传入输入的来源以及与局部抑制性中间神经元的电路连接。 其分化背后的机制对于理解海马的发育和功能至关重要 在健康和疾病中，CA1 的浅表锥体细胞优先表达转录。 调节因子 Satb2，通过改变人类染色质结构来控制基因表达。 Satb2 会导致发育迟缓、智力障碍、癫痫和自闭症行为。 表明在小鼠早期发育过程中敲除 Satb2 会破坏浅表细胞的分化 此外，CA1 中的锥体细胞的迁移和存活存在非细胞自主变化。 相对于对照，突变小鼠的中间神经元具有不同的亚型。 目的将检验 Satb2 的早期表达对于海马锥体细胞是必需的假设 CA1 中的分化和电路发育，而后期表达对于促进体验是必要的- 这些实验将在小鼠中使用分子遗传工具来有条件地实现突触可塑性。 目标 1 将在早期和晚期发育阶段从锥体细胞中敲除 Satb2。 电生理学和电刺激研究不同传入源的强度和可塑性 输入急性切片中的深层和浅层 CA1 锥体细胞，该目的将检验早期的假设。 Satb2 表达对于建立传入输入强度的差异是必要的，而后来的表达是 目标 2 将使用配对的全细胞记录。 锥体细胞（深层和浅层）之间和已识别的中间神经元亚型之间，以绘制电路图和 研究其突触生理学的细节这一目标将检验早期 Satb2 表达的假设。 对于在局部抑制性中间神经元和浅表锥体细胞之间建立电路基序是必要的，同时 后期表达对于招募新的抑制性突触以响应环境富集是必要的。 3 将使用单细胞 RNA-seq 和 ATAC-seq 来确定 Satb2 敲除如何改变基因表达和 CA1 中染色质在多个发育时间点的可及性将提供分子洞察。 Satb2 如何在发育过程中控制 CA1 中的基因表达，以及其功能如何随时间变化。