Zhou Qiang, Tao Huizhong W, Poo Mu-ming
Division of Neurobiology, Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720-3200, USA.
Science. 2003 Jun 20;300(5627):1953-7. doi: 10.1126/science.1082212.
Persistent synaptic modifications are essential for experience-dependent refinement of developing circuits. However, in the developing Xenopus retinotectal system, activity-induced synaptic modifications were quickly reversed either by subsequent spontaneous activity in the tectum or by exposure to random visual inputs. This reversal depended on the burst spiking and activation of the N-methyl-D-aspartate subtype of glutamate receptors. Stabilization of synaptic modifications can be achieved by an appropriately spaced pattern of induction stimuli. These findings underscore the vulnerable nature of activity-induced synaptic modifications in vivo and suggest a temporal constraint on the pattern of visual inputs for effective induction of stable synaptic modifications.
持续性突触修饰对于发育中神经回路的经验依赖性精细化至关重要。然而，在发育中的非洲爪蟾视网膜顶盖系统中，活动诱导的突触修饰会迅速被顶盖随后的自发活动或随机视觉输入所逆转。这种逆转依赖于谷氨酸受体N-甲基-D-天冬氨酸亚型的爆发式放电和激活。通过适当间隔的诱导刺激模式可以实现突触修饰的稳定。这些发现强调了体内活动诱导的突触修饰的脆弱性，并表明有效诱导稳定突触修饰对视觉输入模式存在时间限制。
