Department of Epileptology, Neurology, RWTH Aachen University Hospital Aachen, Aachen, Germany.
Systems Neurophysiology, Institute of Zoology, RWTH Aachen University, Aachen, Germany.
J Neurophysiol. 2024 Sep 1;132(3):1038-1055. doi: 10.1152/jn.00178.2024. Epub 2024 Aug 14.
Murine organotypic brain slice cultures have been widely used in neuroscientific research and are offering the opportunity to study neuronal function under normal and disease conditions. Despite the broad application, the mechanisms governing the maturation of immature cortical circuits in vitro are not well understood. In this study, we present a detailed investigation into the development of the neocortex in vitro. Using a holistic approach, we studied organotypic whole hemisphere brain slice cultures from postnatal mice and tracked the development of the somatosensory area over a 5-wk period. Our analysis revealed the maturation of passive and active intrinsic properties of pyramidal cells together with their morphology, closely resembling in vivo development. Detailed multielectrode array (MEA) electrophysiological assessments and RNA expression profiling demonstrated stable network properties by 2 wk in culture, followed by the transition of spontaneous activity toward more complex patterns including high-frequency oscillations. However, culturing weeks 4 and 5 exhibited increased variability and initial signs of neuronal loss, highlighting the importance of considering developmental stages in experimental design. This comprehensive characterization is vital for understanding the temporal dynamics of the neocortical development in vitro, with implications for neuroscientific research methodologies, particularly in the investigation of diseases such as epilepsy and other neurodevelopmental disorders. The development of the mouse neocortex in vitro mimics the in vivo development. Mouse brain cultures can serve as a model system for cortical development for the first 2 wk in vitro and as a model system for the adult cortex from 2 to 4 wk in vitro. Mouse organotypic brain slice cultures develop high-frequency network oscillations at γ frequency after 2 wk in vitro. Mouse brain cultures exhibit increased heterogeneity and variability after 4 wk in culture.
鼠脑器官型脑片培养已广泛应用于神经科学研究，为研究正常和疾病状态下神经元功能提供了机会。尽管应用广泛，但体外未成熟皮质回路成熟的调控机制仍不清楚。在这项研究中，我们对体外新皮层的发育进行了详细研究。采用整体方法，我们研究了来自新生小鼠的器官型全脑半球脑片培养物，并在 5 周的时间内追踪体感区的发育情况。我们的分析揭示了锥体神经元的被动和主动内在特性及其形态的成熟，与体内发育非常相似。详细的多电极阵列（MEA）电生理评估和 RNA 表达谱分析表明，培养 2 周后网络特性稳定，随后自发活动向包括高频振荡在内的更复杂模式转变。然而，培养第 4 和第 5 周表现出更高的变异性和神经元丢失的初始迹象，这强调了在实验设计中考虑发育阶段的重要性。这种全面的特征对于理解体外新皮层发育的时间动态至关重要，对神经科学研究方法具有重要意义，特别是在癫痫等疾病和其他神经发育障碍的研究中。体外鼠新皮层的发育模拟了体内的发育。体外培养的小鼠脑可以作为前 2 周体外皮质发育的模型系统，也可以作为第 2 至 4 周体外成年皮质的模型系统。体外培养 2 周后，鼠脑器官型脑片培养物在γ频率下产生高频网络振荡。体外培养 4 周后，鼠脑培养物表现出更高的异质性和变异性。
