Tang Ai-Hui, Chai Zhen, Wang Shi-Qiang
State Key Laboratory of Biomembrane and Membrane Biotechnology, College of Life Sciences, Peking University, Beijing 100871, China.
Neurosci Lett. 2007 Jul 5;422(1):49-53. doi: 10.1016/j.neulet.2007.05.053. Epub 2007 Jun 3.
The strength of all chemical synapses can be rapidly up- or down-regulated by their recent activities to reshape the postsynaptic signal through a mechanism of short-term facilitation or depression. It is also true that sensory experience is essential for maturation of cortical circuits and function. We studied the effect of sensory experience on the short-term plasticity in brain slices of rat visual cortex. Repetitive stimulation was applied in layer II/III and the response of pyramidal neuron in layer V was examined by whole-cell recording. We deprived the visual experience of rats by rearing the animals in dark environment. We found that dark rearing (DR) had no effects on paired-pulse interactions of either excitatory postsynaptic currents (EPSCs) or inhibitory postsynaptic currents (IPSCs). However, DR increased the level of IPSCs steady-state depression at stimulation frequency of 20Hz or more. This result, together with the finding that DR reduced the excitability of neural circuit in visual cortex, suggested a compensatory mechanism, which may be important in enhancing the network excitability at a time when synapses are immature.
所有化学突触的强度可通过其近期活动迅速上调或下调，以通过短期易化或抑制机制重塑突触后信号。感觉经验对于皮质回路和功能的成熟也至关重要。我们研究了感觉经验对大鼠视觉皮质脑片短期可塑性的影响。在II/III层施加重复刺激，并通过全细胞记录检查V层锥体细胞的反应。我们通过在黑暗环境中饲养动物来剥夺大鼠的视觉经验。我们发现，黑暗饲养（DR）对兴奋性突触后电流（EPSC）或抑制性突触后电流（IPSC）的双脉冲相互作用均无影响。然而，DR在20Hz或更高的刺激频率下增加了IPSC稳态抑制水平。这一结果，连同DR降低视觉皮质神经回路兴奋性的发现，提示了一种补偿机制，这在突触不成熟时增强网络兴奋性方面可能很重要。
