Department of Pharmacology, Oxford University, Oxford, UK.
Nat Neurosci. 2010 Sep;13(9):1098-106. doi: 10.1038/nn.2612. Epub 2010 Aug 8.
During the development of sensory systems, receptive fields are modified by stimuli in the environment. This is thought to rely on learning algorithms that are sensitive to correlations in spike timing between cells, but the manner in which developing circuits selectively exploit correlations that are related to sensory inputs is unknown. We recorded from neurons in the developing optic tectum of Xenopus laevis and found that repeated presentation of moving visual stimuli induced receptive field changes that reflected the properties of the stimuli and that this form of learning was disrupted when GABAergic transmission was blocked. Consistent with a role for spike timing-dependent mechanisms, GABA blockade altered spike-timing patterns in the tectum and increased correlations between cells that would affect plasticity at intratectal synapses. This is a previously unknown role for GABAergic signals in development and highlights the importance of regulating the statistics of spiking activity for learning.
在感觉系统的发育过程中，感受野会被环境中的刺激所改变。这被认为依赖于对细胞间尖峰时间相关性敏感的学习算法，但发育中的电路以何种方式选择性地利用与感觉输入相关的相关性尚不清楚。我们记录了非洲爪蟾发育中的视顶盖神经元的活动，发现反复呈现运动视觉刺激会诱导感受野的变化，反映出刺激的特性，而当 GABA 能传递被阻断时，这种形式的学习就会受到干扰。与尖峰时间依赖机制的作用一致，GABA 阻断改变了视顶盖中的尖峰时间模式，并增加了细胞之间的相关性，这会影响脑内突触的可塑性。这是 GABA 能信号在发育中的一个以前未知的作用，突出了调节尖峰活动统计对学习的重要性。
