Institute of Neuroscience and State Key Laboratory of Neuroscience, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China.
Neuron. 2012 Aug 9;75(3):479-89. doi: 10.1016/j.neuron.2012.05.031.
Neural activity-induced long-term potentiation (LTP) of synaptic transmission is believed to be one of the cellular mechanisms underlying experience-dependent developmental refinement of neural circuits. Although it is well established that visual experience and neural activity are critical for the refinement of retinal circuits, whether and how LTP occurs in the retina remain unknown. Using in vivo perforated whole-cell recording and two-photon calcium imaging, we find that both repeated electrical and visual stimulations can induce LTP at excitatory synapses formed by bipolar cells on retinal ganglion cells in larval but not juvenile zebrafish. LTP induction requires the activation of postsynaptic N-methyl-D-aspartate receptors, and its expression involves arachidonic acid-dependent presynaptic changes in calcium dynamics and neurotransmitter release. Physiologically, both electrical and visual stimulation-induced LTP can enhance visual responses of retinal ganglion cells. Thus, LTP exists in developing retinae with a presynaptic locus and may serve for visual experience-dependent refinement of retinal circuits.
神经活动诱导的突触传递长时程增强（LTP）被认为是经验依赖性神经回路发育精细化的细胞机制之一。尽管已经证实视觉经验和神经活动对于视网膜回路的精细化至关重要，但 LTP 是否以及如何在视网膜中发生仍不清楚。本研究使用体内穿孔全细胞记录和双光子钙成像技术，发现重复的电刺激和视觉刺激均可在幼虫而非幼年斑马鱼的双极细胞形成的视网膜神经节细胞的兴奋性突触上诱导 LTP。LTP 的诱导需要激活突触后 N-甲基-D-天冬氨酸受体，其表达涉及花生四烯酸依赖性钙动力学和神经递质释放的突触前变化。在生理上，电刺激和视觉刺激诱导的 LTP 均可增强视网膜神经节细胞的视觉反应。因此，LTP 存在于具有突触前位置的发育中的视网膜中，可能用于视觉经验依赖性的视网膜回路精细化。
