Howard Hughes Medical Institute and The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, , 77 Massachusetts Avenue, Cambridge, MA 02139, USA.
Philos Trans R Soc Lond B Biol Sci. 2013 Dec 2;369(1633):20130284. doi: 10.1098/rstb.2013.0284. Print 2014 Jan 5.
Donald Hebb chose visual learning in primary visual cortex (V1) of the rodent to exemplify his theories of how the brain stores information through long-lasting homosynaptic plasticity. Here, we revisit V1 to consider roles for bidirectional 'Hebbian' plasticity in the modification of vision through experience. First, we discuss the consequences of monocular deprivation (MD) in the mouse, which have been studied by many laboratories over many years, and the evidence that synaptic depression of excitatory input from the thalamus is a primary contributor to the loss of visual cortical responsiveness to stimuli viewed through the deprived eye. Second, we describe a less studied, but no less interesting form of plasticity in the visual cortex known as stimulus-selective response potentiation (SRP). SRP results in increases in the response of V1 to a visual stimulus through repeated viewing and bears all the hallmarks of perceptual learning. We describe evidence implicating an important role for potentiation of thalamo-cortical synapses in SRP. In addition, we present new data indicating that there are some features of this form of plasticity that cannot be fully accounted for by such feed-forward Hebbian plasticity, suggesting contributions from intra-cortical circuit components.
唐纳德·赫布（Donald Hebb）选择在啮齿动物的初级视觉皮层（V1）中进行视觉学习，以此为例来说明他的大脑如何通过长时程同源突触可塑性存储信息的理论。在这里，我们重新审视 V1，以考虑双向“赫布式”可塑性在通过经验改变视觉中的作用。首先，我们讨论了多年来许多实验室研究的单眼剥夺（MD）在小鼠中的后果，以及证据表明，来自丘脑的兴奋性输入的突触抑制是剥夺眼观看的刺激导致视觉皮层反应性丧失的主要原因。其次，我们描述了一种在视觉皮层中研究较少但同样有趣的可塑性形式，称为刺激选择性反应增强（SRP）。SRP 通过重复观看导致 V1 对视觉刺激的反应增加，具有感知学习的所有特征。我们描述了证据表明，丘脑皮层突触的增强在 SRP 中起着重要作用。此外，我们提供了新的数据，表明这种形式的可塑性有些特征不能完全用这种前馈赫布式可塑性来解释，这表明皮质内电路成分的贡献。
