Brain-on-a-chip systems are designed to simulate brain activity using traditional in vitro cell culture on an engineered platform. It is a noninvasive tool to screen new drugs, evaluate toxicants, and elucidate disease mechanisms. However, successful recapitulation of brain function on these systems is dependent on the complexity of the cell culture. In this study, we increased cellular complexity of traditional (simple) neuronal cultures by co-culturing with astrocytes and oligodendrocyte precursor cells (complex culture). We evaluated and compared neuronal activity (e.g., network formation and maturation), cellular composition in long-term culture, and the transcriptome of the two cultures. Compared to simple cultures, neurons from complex co-cultures exhibited earlier synapse and network development and maturation, which was supported by localized synaptophysin expression, up-regulation of genes involved in mature neuronal processes, and synchronized neural network activity. Also, mature oligodendrocytes and reactive astrocytes were only detected in complex cultures upon transcriptomic analysis of age-matched cultures. Functionally, the GABA antagonist bicuculline had a greater influence on bursting activity in complex versus simple cultures. Collectively, the cellular complexity of brain-on-a-chip systems intrinsically develops cell type-specific phenotypes relevant to the brain while accelerating the maturation of neuronal networks, important features underdeveloped in traditional cultures.

片上大脑系统设计为在工程平台上使用传统的体外细胞培养来模拟大脑活动。它是一种筛选新药，评估有毒物质并阐明疾病机制的非侵入性工具。然而，在这些系统上大脑功能的成功概括取决于细胞培养的复杂性。在这项研究中，我们通过与星形胶质细胞和少突胶质细胞前体细胞（复合培养）共同培养，增加了传统（简单）神经元培养的细胞复杂性。我们评估并比较了神经元的活动（例如网络形成和成熟），长期培养的细胞组成以及两种培养的转录组。与简单的文化相比，来自复杂共文化的神经元显示出更早的突触和网络发展与成熟，局部突触素表达，成熟神经元过程中涉及的基因上调和同步神经网络活动均支持这种方法。同样，仅在年龄匹配的培养物的转录组分析中，才在复杂的培养物中检测到成熟的少突胶质细胞和反应性星形胶质细胞。在功能上，相对于简单培养，GABA拮抗剂双小分子对爆裂活性的影响更大。总的来说，单芯片大脑系统的细胞复杂性会内在地发展与大脑相关的特定于细胞类型的表型，同时加速神经网络的成熟，这是传统文化中欠发达的重要特征。仅根据年龄匹配的培养物的转录组分析，才能在复杂的培养物中检测到成熟的少突胶质细胞和反应性星形胶质细胞。在功能上，相对于简单培养，GABA拮抗剂双小分子对爆裂活性的影响更大。总的来说，单芯片大脑系统的细胞复杂性会内在地发展与大脑相关的特定于细胞类型的表型，同时加速神经网络的成熟，这是传统文化中欠发达的重要特征。仅根据年龄匹配的培养物的转录组分析，才在复杂的培养物中检测到成熟的少突胶质细胞和反应性星形胶质细胞。在功能上，相对于简单培养，GABA拮抗剂双小分子对爆裂活性的影响更大。总的来说，单芯片大脑系统的细胞复杂性会内在地发展与大脑相关的特定于细胞类型的表型，同时加速神经网络的成熟，这是传统文化中欠发达的重要特征。