Ming Yixuan, Abedin Md Joynal, Tatic-Lucic Svetlana, Berdichevsky Yevgeny
Department of Electrical & Computer Engineering, Lehigh University, Bethlehem, PA USA.
Department of Bioengineering, Lehigh University, Bethlehem, PA USA.
Microsyst Nanoeng. 2021 Sep 1;7:67. doi: 10.1038/s41378-021-00292-9. eCollection 2021.
Neuronal cultures are widely used in neuroscience research. However, the randomness of circuits in conventional cultures prevents accurate in vitro modeling of cortical development and of the pathogenesis of neurological and psychiatric disorders. A basic feature of cortical circuits that is not captured in standard cultures of dissociated cortical cells is directional connectivity. In this work, a polydimethylsiloxane (PDMS)-based device that achieves directional connectivity between micro 3D cultures is demonstrated. The device consists of through-holes for micro three-dimensional (μ3D) clusters of cortical cells connected by microtrenches for axon and dendrite guidance. The design of the trenches relies in part on the concept of axonal edge guidance, as well as on the novel concept of specific dendrite targeting. This replicates dominant excitatory connectivity in the cortex, enables the guidance of the axon after it forms a synapse in passing (an "en passant" synapse), and ensures that directional selectivity is preserved over the lifetime of the culture. The directionality of connections was verified morphologically and functionally. Connections were dependent on glutamatergic synapses. The design of this device has the potential to serve as a building block for the reconstruction of more complex cortical circuits in vitro.
神经元培养物在神经科学研究中被广泛应用。然而，传统培养物中回路的随机性阻碍了对皮质发育以及神经和精神疾病发病机制进行准确的体外建模。解离的皮质细胞的标准培养物无法捕捉到的皮质回路的一个基本特征是定向连接性。在这项工作中，展示了一种基于聚二甲基硅氧烷（PDMS）的装置，该装置可在微型3D培养物之间实现定向连接。该装置由用于皮质细胞微型三维（μ3D）簇的通孔组成，这些通孔通过用于轴突和树突引导的微槽相连。微槽的设计部分依赖于轴突边缘引导的概念，以及特定树突靶向的新概念。这复制了皮质中主要的兴奋性连接，使得轴突在形成“路过”突触（“en passant”突触）后能够被引导，并确保在培养物的整个生命周期内保持定向选择性。连接的方向性在形态学和功能上得到了验证。连接依赖于谷氨酸能突触。该装置的设计有潜力作为体外重建更复杂皮质回路的一个构建模块。
