Kang Seong Jun, Nguyen Huu Son, Lee Choong-Ku, Kim Sohyun, Rhee Jeong Seop, Jeong Seong-Woo
Department of Physiology, Yonsei University Wonju College of Medicine, Ilsan-ro 20, Wonju, Gangwon-do, Republic of Korea.
Max-Planck Institute for Multidisciplinary Sciences, City Campus, Synaptic Physiology Group, Göttingen, Germany.
Pflugers Arch. 2025 Jan;477(1):111-129. doi: 10.1007/s00424-024-03023-x. Epub 2024 Sep 26.
An autaptic synapse (or 'autapse') is a functional connection between a neuron and itself, commonly used in studying the molecular mechanisms underlying synaptic transmission and plasticity in central neurons. Most previous studies on autonomic synaptic functions have relied on spontaneous connections among neurons in mass cultures. However, growing evidence supports the utility of microcultures cultivating autaptic neurons for examining cholinergic transmission within sympathetic ganglia. Despite these advancements, standardized protocols for culturing autaptic sympathetic neurons have yet to be established. Drawing on historical literature, this study delineates optimal experimental conditions to efficiently and reliably produce cholinergic synapses in sympathetic neurons within a short time frame. Our research emphasizes five key factors: (i) the generation of uniformly sized microislands of growth permissive substrates; (ii) the addition of nerve growth factor, ciliary neurotrophic factor (CNTF), and serum to the culture medium; (iii) independence from specific serum and neuronal medium types; (iv) the reciprocal roles of CNTF and glial cells; and (v) the promotion of cholinergic synaptogenesis in SCG neurons through indirect glia co-cultures, rather than direct glial feeder layer cultures. In conclusion, glia-free monocultures of SCG neurons are relatively simple to prepare and yield robust and reliable synaptic currents. This makes them an effective model system for straightforwardly addressing fundamental questions about neurogenic mechanisms involved in cholinergic synaptic transmission in autonomic ganglia. Furthermore, autaptic culture experiments could eventually be implemented to investigate the roles of functional neuron-satellite glia units in regulating cholinergic functions under physiological and pathological conditions.
自突触（或“自身突触”）是神经元与其自身之间的功能性连接，常用于研究中枢神经元突触传递和可塑性的分子机制。以往大多数关于自主突触功能的研究都依赖于大规模培养中神经元之间的自发连接。然而，越来越多的证据支持利用微培养法培养自突触神经元来研究交感神经节内的胆碱能传递。尽管有这些进展，但用于培养自突触交感神经元的标准化方案尚未建立。借鉴历史文献，本研究描述了在短时间内高效、可靠地在交感神经元中产生胆碱能突触的最佳实验条件。我们的研究强调了五个关键因素：（i）生成大小均匀的允许生长底物微岛；（ii）在培养基中添加神经生长因子、睫状神经营养因子（CNTF）和血清；（iii）不依赖特定的血清和神经元培养基类型；（iv）CNTF和神经胶质细胞的相互作用；（v）通过间接神经胶质细胞共培养而非直接神经胶质饲养层培养促进SCG神经元中的胆碱能突触形成。总之，SCG神经元的无胶质单培养相对容易制备，并能产生强大而可靠的突触电流。这使其成为一个有效的模型系统，可直接解决有关自主神经节中胆碱能突触传递所涉及的神经发生机制的基本问题。此外，最终可以进行自突触培养实验，以研究功能性神经元 - 卫星神经胶质细胞单元在生理和病理条件下调节胆碱能功能中的作用。
