Neurosciences Graduate Program, University of California, San Diego, La Jolla, California 92093, USA.
Nat Rev Neurosci. 2010 Jan;11(1):18-29. doi: 10.1038/nrn2759. Epub 2009 Dec 2.
Patterned, spontaneous activity occurs in many developing neural circuits, including the retina, the cochlea, the spinal cord, the cerebellum and the hippocampus, where it provides signals that are important for the development of neurons and their connections. Despite there being differences in adult architecture and output across these various circuits, the patterns of spontaneous network activity and the mechanisms that generate it are remarkably similar. The mechanisms can include a depolarizing action of GABA (gamma-aminobutyric acid), transient synaptic connections, extrasynaptic transmission, gap junction coupling and the presence of pacemaker-like neurons. Interestingly, spontaneous activity is robust; if one element of a circuit is disrupted another will generate similar activity. This research suggests that developing neural circuits exhibit transient and tunable features that maintain a source of correlated activity during crucial stages of development.
在许多发育中的神经回路中，包括视网膜、耳蜗、脊髓、小脑和海马体，都会出现有规律的自发性活动，这些活动为神经元及其连接的发育提供了重要信号。尽管这些不同的回路在成年后的结构和输出上存在差异，但自发性网络活动的模式以及产生这些活动的机制却非常相似。这些机制可能包括 GABA（γ-氨基丁酸）的去极化作用、短暂的突触连接、突触外传递、缝隙连接耦合以及类似起搏器的神经元的存在。有趣的是，自发性活动具有很强的稳定性；如果一个回路的某个元件受到干扰，另一个元件将会产生类似的活动。这项研究表明，发育中的神经回路具有短暂和可调的特性，在发育的关键阶段维持着相关活动的来源。
